Difference between revisions of "Willow"

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{alternateuses}}
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{{SPlantbox
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{{Taxobox
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|familia=Salicaceae
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| color = lightgreen
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|genus=Salix
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| name = Willows
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|common_name=Willow, Osier
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| image = Willow.jpg
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|name_ref=Flora - A Gardener's Encyclopedia
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| image_width = 270px
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|exposure=sun
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| image_caption = Weeping Willow
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|sun_ref=Sunset National Garden Book
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| regnum = [[Plant]]ae
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|water=wet, moist
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| divisio = [[Flowering plant|Magnoliophyta]]
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|water_ref=Sunset National Garden Book
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| classis = [[Dicotyledon|Magnoliopsida]]
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|Temp Metric=°F
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| ordo = [[Malpighiales]]
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|sunset_zones=varies by species
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| familia = [[Salicaceae]]
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|jumpin=If this plant info box on watering; zones; height; etc. is mostly empty you can click on the edit tab and fill in the blanks!
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| genus = '''''Salix''''' [[Carolus Linnaeus|L.]]
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|image=Willow.jpg
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| subdivision_ranks = Species
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|image_width=200
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| subdivision =
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|image_caption=Weeping Willow
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}}
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'''Willows''', '''sallows''', and '''osiers''' form the [[genus]] '''''Salix''''', around 400 species<ref name=Mabberley>Mabberley, D.J. 1997. The Plant Book. Cambridge University Press #2: Cambridge.</ref> of [[deciduous]] [[tree]]s and [[shrub]]s, found primarily on moist [[soil]]s in cold and [[temperate]] regions of the [[Northern Hemisphere]]. Most species are known as willow, but some narrow-leaved shrub species are called ''osier'', and some broader-leaved species are referred to as ''sallow'' (derived from the [[Latin]] word ''salix'', willow). Some willows (particularly [[arctic]] and [[alpine climate|alpine]] species) are low-growing or creeping shrubs; for example the Dwarf Willow (''[[Salix herbacea]]'') rarely exceeds {{Convert|6|cm|in|0|abbr=on}} in height, though spreading widely across the ground.
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Willows are very cross-fertile, and numerous [[Hybrid (biology)|hybrid]]s occur, both naturally and in cultivation. A well-known [[ornamental plant|ornamental]] example is the Weeping Willow (''Salix × sepulcralis''), which is a hybrid of Peking Willow (''[[Salix babylonica]]'') from [[China]] and White Willow (''[[Salix alba]]'') from [[Europe]].
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Willows all have abundant watery bark, sap which is heavily charged with [[salicylic acid]], soft, usually pliant, tough wood, slender branches, and large, fibrous, often [[stolon]]iferous roots. The roots are remarkable for their toughness, size, and tenacity to life, and roots readily grow from aerial parts of the plant.
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The [[leaf|leaves]] are typically elongated but may also be round to oval, frequently with a serrated margin. Most species are deciduous; semi-evergreen willows with coriaceous leaves are rare, e.g. ''Salix micans'' and ''S. australior'' in the eastern Mediterranean. All the buds are lateral; no absolutely terminal bud is ever formed. The buds are covered by a single scale, enclosing at its base two minute opposite buds, alternately arranged, with two small, opposite, scale-like leaves. This first pair soon fall, and the later leaves are alternately arranged. The leaves are simple, feather-veined, and typically linear-lanceolate. Usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the [[stipule]]s often very conspicuous, looking like tiny round leaves and sometimes remaining for half the summer.  On some species, however, they are small, inconspicuous, and fugacious (soon falling). In color the leaves show a great variety of greens, ranging from yellowish to bluish.
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{{Inc|
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Salix (ancient Latin name of willow). Salicaceae. Willow. Dioecious trees and shrubs, planted for the foliage and interesting habit, for shade, screens, and cover; flowers in catkins, mostly in spring and in many species very early.
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Erect, or some arctic and alpine species prostrate, glabrous, pubescent or tomentose: lvs. simple, alternate, mostly elongated and pointed, the stipules persistent and prominent or caducous: buds with a single bud-scale: fls. in lax scaly spikes (aments or catkins), each fl. subtended by a single entire scale and nearly or quite destitute of perianth; the staminate fl. with 1,2, or 3-6 stamens; the pistillate fl. of a single pistil composed of 2 carpels and 2 more or less divided stigmas; at maturity the pistil dehisces, setting free the small appendaged seeds.—Species and species-like hybrids probably 300, widely spread in the northern hemisphere and a few in the southern hemisphere; no native species are reported in New Zeal. and Austral. In temperate regions, they are mostly plants of water-courses, shores, and swamps; but a good number run into the far N. and the high elevations where conditions of moisture are maintained. The wood is light, soft, and porous. For the staminate and pistillate fls. of willow, see Fig. 1528, Vol. III. The catkins or "pussies" are also shown in Figs. 3521 and 3522 herewith. In rare cases, a willow may be monoecious.
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Many hybrids have been described based on specimens found in nature that presented characters intermediate between recognized species. Artificial hybrids have also been made between many species. The dioecious habit of the species seems to facilitate cross- pollination, and it is probable that the intermediate forms so frequently met with and designated in the monographs as varieties are natural hybrids. Upward of one hundred hybrid willows have been described as growing in Europe. Although as many or even more species occur in America, fewer hybrids have been detected here. The hybrids described as growing in America are for the most part between native species and those introduced from Europe. Because of the hybridity and the fact that the sexes are separated, the genus Salix is considered to be very critical and difficult for the systematist.
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The role that the willow plays in the north temperate regions is to a certain extent analogous to that of the eucalyptus in subtropical regions; it flourishes in wet ground and absorbs and transpires immense quantities of water. It has been used to plant around cesspools for sanitary effect. But while most of the species occur spontaneously in wet ground or along stream-banks, the willows may be cultivated in various situations. The white willow (S. alba) has been used very effectively to fix stream-banks against erosion. Its root-system is very extensive and when well established withstands the effect of heavy rapid streams as well as wave-action. S. arctica and several allied species are among the few woody plants extending into extreme arctic regions. The arctic species are among the most diminutive of woody plants. As one goes south the species increase in size. Some of the species of North Temperate, Tropical and South Temperate zones are large trees. The arborescent species all form wood very rapidly. Specimens of white willow which may not be of great age look venerable from their great thickness of trunk and size of top. The wood is light in weight and color, finely and evenly porous. The wood has been extensively used in manufacture of gunpowder. It has also been used for many other purposes. Certain species have been extensively cultivated for many years in Europe for materials with which to manufacture baskets. S. viminalis appears to be the favorite species for this purpose. Basket willow is now extensively planted in central New York, and considerable manufacturing of this material is under way.
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As ornamental trees the willows present little variety. The bright yellow catkins of some species are attractive in spring. They are considerably used as "nurse trees" for slower-growing trees that require partial shade while young. The red and yellow branches of certain willows are very bright and cheering in winter. The weeping forms are very popular, but they are often planted with little sense of fitness. The cultural remarks under Populus will apply to willows.
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The species of willows are readily propagated by cuttings. It has been suggested that the brittleness at base of twigs of some species, notably the black willow (S. nigra), is an adaptation to facilitate the natural distribution of the species. Certain it is that twigs broken from the tree by the wind are carried down streams and, becoming anchored in the muddy banks, grow readily. It is one of the most aggressive trees in occupying such places. Willows may also be propagated by seed. The seeds are very small and contain a green and short-lived embryo. A very short exposure of the seeds to the air will so dry them out that they will not germinate. The safest way to secure seedlings is to plant the seeds as soon as the capsule opens.
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}}
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==Cultivation==
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Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the Goat Willow (''[[Salix caprea]]'') and Peachleaf Willow (''[[Salix amygdaloides]]''). One famous example of such growth from cuttings involves the poet [[Alexander Pope]], who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's weeping willows are descended from this first one.<ref>{{cite web |url=http://www.uab.edu/english/hone/etexts/edb/day-pages/221-aug09.html |title=August 9 |first=William |last=Hone |authorlink=William Hone |work=The Every-Day Book (Electronic Edition) |year=1826}} Hone quotes "Martyn", and notes that Martyn in turn cites "the ''St. James's Chronicle'', for August, 1801".</ref>
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Willows are often planted on the borders of streams so that their interlacing roots may protect the bank against the action of the water. Frequently the roots are much larger than the stem which grows from them.
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===Propagation===
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{{edit-prop}}<!--- Type propagation info below this line, then delete this entire line -->
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===Pests and diseases===
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{{edit-pests}}<!--- Type pest/disease info below this line, then delete this entire line -->
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==Species==
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About 350, including:<br/>
 
About 350, including:<br/>
 
''[[Salix acutifolia]]'' - [[Violet Willow]]<br/>
 
''[[Salix acutifolia]]'' - [[Violet Willow]]<br/>
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''[[Salix eriocephala]]'' - [[Heartleaf Willow]]<br/>
 
''[[Salix eriocephala]]'' - [[Heartleaf Willow]]<br/>
 
''[[Salix exigua]]'' - [[Sandbar Willow]]<br/>
 
''[[Salix exigua]]'' - [[Sandbar Willow]]<br/>
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''[[Salix fargesii]]'' <br/>
 
''[[Salix foetida]]'' <br/>
 
''[[Salix foetida]]'' <br/>
 
''[[Salix fragilis]]'' - [[Crack Willow]]<br/>
 
''[[Salix fragilis]]'' - [[Crack Willow]]<br/>
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''[[Salix gracilistyla]]''<br/>
 
''[[Salix gracilistyla]]''<br/>
 
''[[Salix hainanica]]'' - [[Hainan Willow]]<br/>
 
''[[Salix hainanica]]'' - [[Hainan Willow]]<br/>
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''[[Salix hastata]]''<br/>
 
''[[Salix helvetica]]'' - [[Swiss Willow]]<br/>
 
''[[Salix helvetica]]'' - [[Swiss Willow]]<br/>
 
''[[Salix herbacea]]'' - [[Dwarf Willow]]<br/>
 
''[[Salix herbacea]]'' - [[Dwarf Willow]]<br/>
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''[[Salix integra]]''<br/>
 
''[[Salix integra]]''<br/>
 
''[[Salix interior]]''<br/>
 
''[[Salix interior]]''<br/>
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''[[Salix irrorata]]''<br/>
 
''[[Salix japonica]]''<br/>
 
''[[Salix japonica]]''<br/>
 
''[[Salix jessoensis]]''<br/>
 
''[[Salix jessoensis]]''<br/>
 
''[[Salix koriyanagi]]''<br/>
 
''[[Salix koriyanagi]]''<br/>
 
''[[Salix kusanoi]]''<br/>
 
''[[Salix kusanoi]]''<br/>
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''[[Salix laevigata]]''<br/>
 
''[[Salix lanata]]'' - [[Woolly Willow]]<br/>
 
''[[Salix lanata]]'' - [[Woolly Willow]]<br/>
 
''[[Salix lapponum]]'' - [[Downy Willow]]<br/>
 
''[[Salix lapponum]]'' - [[Downy Willow]]<br/>
 
''[[Salix lasiandra]]'' - [[Pacific Willow]]<br/>
 
''[[Salix lasiandra]]'' - [[Pacific Willow]]<br/>
 
''[[Salix lasiolepsis]]'' - [[Arroyo Willow]]<br/>
 
''[[Salix lasiolepsis]]'' - [[Arroyo Willow]]<br/>
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''[[Salix lindleyana]]''<br/>
 
''[[Salix lucida]]'' - [[Shining Willow]]<br/>
 
''[[Salix lucida]]'' - [[Shining Willow]]<br/>
 
''[[Salix magnifica]]''<br/>
 
''[[Salix magnifica]]''<br/>
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''[[Salix reinii]]''<br/>
 
''[[Salix reinii]]''<br/>
 
''[[Salix repens]]'' - [[Creeping Willow]]<br/>
 
''[[Salix repens]]'' - [[Creeping Willow]]<br/>
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''[[Salix reptans]]''<br/>
 
''[[Salix reticulata]]'' - [[Net-leaved Willow]]<br/>
 
''[[Salix reticulata]]'' - [[Net-leaved Willow]]<br/>
 
''[[Salix retusa]]''<br/>
 
''[[Salix retusa]]''<br/>
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''[[Salix schwerinii]]''<br/>
 
''[[Salix schwerinii]]''<br/>
 
''[[Salix scouleriana]]'' - [[Scouler's Willow]]<br/>
 
''[[Salix scouleriana]]'' - [[Scouler's Willow]]<br/>
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''[[Salix sericea]]'' - [[Sil
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''[[Salix sericea]]'' - [[Silky Willow]]<br/>
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ky Willow]]<br/>
 
 
''[[Salix serissaefolia]]''<br/>
 
''[[Salix serissaefolia]]''<br/>
 
''[[Salix serissima]]'' - [[Autumn Willow]]<br/>
 
''[[Salix serissima]]'' - [[Autumn Willow]]<br/>
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''[[Salix subopposita]]''<br/>
 
''[[Salix subopposita]]''<br/>
 
''[[Salix taraikensis]]''<br/>
 
''[[Salix taraikensis]]''<br/>
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''[[Salix taxifolia]]''<br/>
 
''[[Salix tetrasperma]]''<br/>
 
''[[Salix tetrasperma]]''<br/>
 
''[[Salix thorelii]]''<br/>
 
''[[Salix thorelii]]''<br/>
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''[[Salix yezoalpina]]''<br/>
 
''[[Salix yezoalpina]]''<br/>
 
''[[Salix yoshinoi]]''<br/>
 
''[[Salix yoshinoi]]''<br/>
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}}
 
  
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The '''willows''' are [[deciduous]] [[tree]]s and [[shrub]]s in the genus '''''Salix''''', part of the willow family [[Salicaceae]].
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Hybrids:
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*''[[Salix x rubens]]''
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*''[[Salix x sepulcralis]]''
  
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There are about 350 species in this genus worldwide, found primarily on moist [[soil]]s in cooler zones in the [[Northern Hemisphere]]. The [[leaf|leaves]] are deciduous, often elongate but round to oval in a few species, and with a serrated margin. Willows are [[plant sexuality|dioecious]] with male and female [[flower]]s appearing as [[catkin]]s on different plants; the catkins are produced early in the spring, often before the leaves or as the new leaves open. The [[fruit]] is a small [[capsule (fruit)|capsule]] containing numerous tiny (0.1 mm) [[seed]]s embedded in white down, which assists wind dispersal of the seeds. Willows are very cross-fertile and numerous [[hybrid]]s are known, both naturally occurring and in cultivation.
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Cultivars:
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*[[Salix 'Boydii']]
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*[[Salix 'Flame']]
  
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Some smaller species may also be known by the common names ''osier'' and ''sallow''; the latter name is derived from the same root as the [[Latin]] ''salix''.
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{{Inc|
  
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Some willows, particularly [[arctic]] and [[alpine climate|alpine]] species, are very small; the '''Dwarf Willow''' (''Salix herbacea'') rarely exceeds 6 cm in height, though spreading widely across the ground.
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S. aglaia, Hort.-S. daphnoides.—S. amygdalina, Linn. (S. triandra. Linn.). Usually shrubby, to 12 ft.: branchlets glabrous, rarely slightly silky: lvs. lanceolate, glabrous, pale green or bluish below, to 5 in. long: fls. shortly before or with the lvs.; stamens 3; ovary long-stalked, glabrous. Eu.—S. Bakeri, Seemen, is probably a form of S. lasiolepis.—S. Bockii, Von Seemen. An ornamental dwarf species: lvs. oblong or oval, 1/4-1/2 in. long, mucronate, dark green and glabrescent above, silvery with silky appressed hairs beneath: aments 1-2 in. long, produced in Oct. and Nov. before the fall of the lvs. China.—S. chrysocoma. Dode, is a hybrid between S. babylonica and S. vitellina.—S. daphnoides, Vill. Ten to 20 ft. high: twigs violet: lvs. narrow-oblong or linear-lanceolate, very acuminate. 3-6 in. long.—S. Hankensonii, Dode. Apparently a natural hybrid between a species of the group of S. nigra and one of the group of S. babylonica.—S. heterandra, Dode. Possibly hybrid between a species of the S. purpurea group and one allied to S. pentandra. Shrub: lvs. lanceolate-obovate or narrowly lanceolate, 3—4 in. long, remotely serrate, glabrous, light green above, whitish- glaucous beneath: male aments about 1 3/4 in. long: Caucasus.—S. hypoleuca, Seemen. Shrub, to 10ft.: lvs. elliptic to lanceolate, acute, glabrous at maturity, glaucous below, 1-2 in. long: aments with the lvs. 1-2 in. long. Cent. W. China.—S. japonica, Thunb. (S. babylonica var. japonica, Anderss.). Shrub, to 6 ft.: lvs. ovate-oblong to lanceolate, remotely serrate, glabrous, grayish green beneath, to 3 in. long: aments slender, 2 1/2-3 1/2 in. long; ovary glabrous. Japan.— S.lasiolepis, Benth. Arroyo Willow. Shrub or tree, 8-25 ft. high: lvs. oblong, suborbicular, obovate or linear acute, obscurely serrulate, 1 1/2-5 in. long: aments appearing before the lvs., sessile, densely silky-tomentose in the bud, suberect: caps. glabrous or puberulent, short-pedicelled. Calif.—S. lispocladus, Dode. Lvs. ovate-lanceolate, about 2 1/2 in. long, serrate, light green and shining above, whitish glaucous beneath: male aments appearing late. Caucasus.— S. magnifica, Hemsl. Shrub, to 20 ft.: lvs. oval to obovate, shortly and obtusely acuminate, glabrous, pale beneath, to 8 in. long and to 5 in. wide; petiole purplish: staminate aments to 7 in., pistillate to 11 in. long. W. China. A remarkable willow, but tender N. J. H.S. 39. p. 137, fig. 148.—S. Matsudana, Koidsumi (S. babylonica var. pekinensis, Henry). Tree, to 40 ft.: branchlets ascending or pendulous, greenish: lvb. narrowly lanceolate, serrulate, glabrous, 2-4 in. long: aments with the lvs., about 1/2 in. long. N. E. Asia.—S. Medemii, Boiss., of the Armenia-Persia region is an upright species 12 ft. and more high with oblong somewhat serrate lvs. abruptly pointed.—S. Medwedewii, Dode. Shrub or small tree: lvs. very narrow, up to 4 in. long: female aments appearing late, cylindric, 1 1/4 in. long. Caucasus.—P. oxica, Dode. Lvs. large, glaucescent, giving the tree a bluish appearance. Cent. Asia.—S. persica, Boiss. Similar to P. babylonica. Trunk pale ashy gray or brownish: lvs. very shortly stalked, somewhat falcate, long-acuminate, serrulate. Persia.—S. Rehderiana, Schneid. Shrub, to 10 ft.: branchlets sparingly hairy or glabrous: lvs. lanceolate, crenulate, whitish and silky beneath, with yellow midrib, 2-5 in. long: aments precocious, about 1 in. long; anthers purple at first; ovaries glabrous. W. China. —S. renecia is a hybrid, of which S. cinerea is a parent.—S. Tominii, Dode. Tree with spreading branches: lvs. obovate to lanceolate, 3 1/3- 4 in. long or more, remotely serrate: male aments at first conical and rosy at apex, afterward ovate-cylindric, 3/4 in. long. W. Asia.—S. triandra, Linn.-S. amygdalina.—S. Wallichiana, Anderss. Shrub or small tree: lvs. ovate- to oblong-lanceolate, entire, silky beneath like the young branchlets, 2-3 in. long: staminate aments 1 in. long, pistillate 3—5 in.: caps slender, silky. Himayalas, Cent. and W. China.—S. zygostemon. Hook. f. & Thorn. Probably a natural hybrid between S. purpurea and S. Medemii.—S. Wentworthii, Hort., is described as a tall upright rapid-growing willow with bright red bark: botanical position to be determined.
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The '''Weeping Willow''', very widely planted as an [[ornamental plant|ornamental tree]], is a [[cultivar]], ''Salix × sepulcralis'' 'Chrysocoma', derived from a hybrid between the [[China|Chinese]] [[Peking Willow]] and the [[Europe]]an [[White Willow]].
 
  
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Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the [[Goat Willow]] and [[Peachleaf Willow]]. One famous example of such growth from cuttings involves the poet [[Alexander Pope]], who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's Weeping Willows are descended from this first one [http://www.uab.edu/english/hone/etexts/edb/day-pages/221-aug09.html].
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==Gallery==
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Willows are used as food plants by the [[larva]]e of some [[Lepidoptera]] species - see [[list of Lepidoptera which feed on Willows]].
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{{photo-sources}}<!-- remove this line if there are already 3 or more photos in the gallery -->
  
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A number of willow species were widely planted in Australia in the past, notably as erosion control measures along watercourses. They are now regarded as an invasive [[weed]] and many catchment management authorities are removing them to be replaced with native trees [http://www.dse.vic.gov.au/dpi/nreninf.nsf/childdocs/-1C62D26CD3AF6FE44A2568B300051289-8E21A59E53B35BEFCA256BC80005C14F-E1EB709D7DCE1BC9CA256F070003E8D8-FAC3FFA202EA6384CA256BCF000AD522?open].. [http://www.hoadley.net/cremer/willows/docs/WillowInBiodiversity.pdf].
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<gallery>
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Image:Upload.png| photo 1
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Image:Upload.png| photo 2
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Image:Upload.png| photo 3
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</gallery>
  
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==Uses==
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==References==
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;Medicinal uses
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*[[Standard Cyclopedia of Horticulture]], by L. H. Bailey, MacMillan Co., 1963
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The bark of the willow tree has been mentioned in ancient texts from [[Assyria]], [[Sumer]] and [[Ancient Egypt|Egypt]] as a remedy for aches and [[fever]], and the [[Ancient Greece|Greek]] physician [[Hippocrates]] wrote about its medicinal properties in the [[5th century BC]]. [[Indigenous peoples of the Americas|Native Americans]] across the American continent relied on it as a staple of their medical treatments.
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<!--- xxxxx  *Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881925381  -->
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<!--- xxxxx  *American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432  -->
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<!--- xxxxx  *Sunset National Garden Book. Sunset Books, Inc., 1997. ISBN 0376038608  -->
  
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The active extract of the bark, called [[salicin]], was isolated to its crystalline form in 1828 by [[Henri Leroux]], a French pharmacist, and [[Raffaele Piria]], an Italian chemist, who then succeeded in separating out the acid in its pure state. Salicin
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==External links==
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is acidic when in a [[saturation (chemistry)|saturated solution]] in water (''p''H = 2.4), and is called [[salicylic acid]] for that reason.
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*{{wplink}}
  
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In 1897 [[Felix Hoffmann]] created a synthetically altered version of salicin (in his case derived from the ''[[Spiraea]]'' plant), which caused less digestive upset than pure salicylic acid. The new drug, formally ''[[Acetylsalicylic acid]]'', was named [[aspirin]] by Hoffmann's employer [[Bayer|Bayer AG]]. This gave rise to the hugely important class of drugs known as [[NSAIDs|non-steroidal anti-inflammatory drugs]] (NSAIDs).
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{{stub}}
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__NOTOC__

Latest revision as of 18:55, 7 May 2010


Weeping Willow


Plant Characteristics
Cultivation
Exposure: ☼ sun
Water: ◍ wet, moist
Sunset Zones: varies by species
Scientific Names

Salicaceae >

Salix >


If this plant info box on watering; zones; height; etc. is mostly empty you can click on the edit tab and fill in the blanks!


Willows, sallows, and osiers form the genus Salix, around 400 species[1] of deciduous trees and shrubs, found primarily on moist soils in cold and temperate regions of the Northern Hemisphere. Most species are known as willow, but some narrow-leaved shrub species are called osier, and some broader-leaved species are referred to as sallow (derived from the Latin word salix, willow). Some willows (particularly arctic and alpine species) are low-growing or creeping shrubs; for example the Dwarf Willow (Salix herbacea) rarely exceeds 6 cm in 0 in height, though spreading widely across the ground.

Willows are very cross-fertile, and numerous hybrids occur, both naturally and in cultivation. A well-known ornamental example is the Weeping Willow (Salix × sepulcralis), which is a hybrid of Peking Willow (Salix babylonica) from China and White Willow (Salix alba) from Europe.

Willows all have abundant watery bark, sap which is heavily charged with salicylic acid, soft, usually pliant, tough wood, slender branches, and large, fibrous, often stoloniferous roots. The roots are remarkable for their toughness, size, and tenacity to life, and roots readily grow from aerial parts of the plant.

The leaves are typically elongated but may also be round to oval, frequently with a serrated margin. Most species are deciduous; semi-evergreen willows with coriaceous leaves are rare, e.g. Salix micans and S. australior in the eastern Mediterranean. All the buds are lateral; no absolutely terminal bud is ever formed. The buds are covered by a single scale, enclosing at its base two minute opposite buds, alternately arranged, with two small, opposite, scale-like leaves. This first pair soon fall, and the later leaves are alternately arranged. The leaves are simple, feather-veined, and typically linear-lanceolate. Usually they are serrate, rounded at base, acute or acuminate. The leaf petioles are short, the stipules often very conspicuous, looking like tiny round leaves and sometimes remaining for half the summer. On some species, however, they are small, inconspicuous, and fugacious (soon falling). In color the leaves show a great variety of greens, ranging from yellowish to bluish.


Read about Willow in the Standard Cyclopedia of Horticulture 

Salix (ancient Latin name of willow). Salicaceae. Willow. Dioecious trees and shrubs, planted for the foliage and interesting habit, for shade, screens, and cover; flowers in catkins, mostly in spring and in many species very early.

Erect, or some arctic and alpine species prostrate, glabrous, pubescent or tomentose: lvs. simple, alternate, mostly elongated and pointed, the stipules persistent and prominent or caducous: buds with a single bud-scale: fls. in lax scaly spikes (aments or catkins), each fl. subtended by a single entire scale and nearly or quite destitute of perianth; the staminate fl. with 1,2, or 3-6 stamens; the pistillate fl. of a single pistil composed of 2 carpels and 2 more or less divided stigmas; at maturity the pistil dehisces, setting free the small appendaged seeds.—Species and species-like hybrids probably 300, widely spread in the northern hemisphere and a few in the southern hemisphere; no native species are reported in New Zeal. and Austral. In temperate regions, they are mostly plants of water-courses, shores, and swamps; but a good number run into the far N. and the high elevations where conditions of moisture are maintained. The wood is light, soft, and porous. For the staminate and pistillate fls. of willow, see Fig. 1528, Vol. III. The catkins or "pussies" are also shown in Figs. 3521 and 3522 herewith. In rare cases, a willow may be monoecious.

Many hybrids have been described based on specimens found in nature that presented characters intermediate between recognized species. Artificial hybrids have also been made between many species. The dioecious habit of the species seems to facilitate cross- pollination, and it is probable that the intermediate forms so frequently met with and designated in the monographs as varieties are natural hybrids. Upward of one hundred hybrid willows have been described as growing in Europe. Although as many or even more species occur in America, fewer hybrids have been detected here. The hybrids described as growing in America are for the most part between native species and those introduced from Europe. Because of the hybridity and the fact that the sexes are separated, the genus Salix is considered to be very critical and difficult for the systematist.

The role that the willow plays in the north temperate regions is to a certain extent analogous to that of the eucalyptus in subtropical regions; it flourishes in wet ground and absorbs and transpires immense quantities of water. It has been used to plant around cesspools for sanitary effect. But while most of the species occur spontaneously in wet ground or along stream-banks, the willows may be cultivated in various situations. The white willow (S. alba) has been used very effectively to fix stream-banks against erosion. Its root-system is very extensive and when well established withstands the effect of heavy rapid streams as well as wave-action. S. arctica and several allied species are among the few woody plants extending into extreme arctic regions. The arctic species are among the most diminutive of woody plants. As one goes south the species increase in size. Some of the species of North Temperate, Tropical and South Temperate zones are large trees. The arborescent species all form wood very rapidly. Specimens of white willow which may not be of great age look venerable from their great thickness of trunk and size of top. The wood is light in weight and color, finely and evenly porous. The wood has been extensively used in manufacture of gunpowder. It has also been used for many other purposes. Certain species have been extensively cultivated for many years in Europe for materials with which to manufacture baskets. S. viminalis appears to be the favorite species for this purpose. Basket willow is now extensively planted in central New York, and considerable manufacturing of this material is under way.

As ornamental trees the willows present little variety. The bright yellow catkins of some species are attractive in spring. They are considerably used as "nurse trees" for slower-growing trees that require partial shade while young. The red and yellow branches of certain willows are very bright and cheering in winter. The weeping forms are very popular, but they are often planted with little sense of fitness. The cultural remarks under Populus will apply to willows.

The species of willows are readily propagated by cuttings. It has been suggested that the brittleness at base of twigs of some species, notably the black willow (S. nigra), is an adaptation to facilitate the natural distribution of the species. Certain it is that twigs broken from the tree by the wind are carried down streams and, becoming anchored in the muddy banks, grow readily. It is one of the most aggressive trees in occupying such places. Willows may also be propagated by seed. The seeds are very small and contain a green and short-lived embryo. A very short exposure of the seeds to the air will so dry them out that they will not germinate. The safest way to secure seedlings is to plant the seeds as soon as the capsule opens.


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Cultivation

Almost all willows take root very readily from cuttings or where broken branches lie on the ground. There are a few exceptions, including the Goat Willow (Salix caprea) and Peachleaf Willow (Salix amygdaloides). One famous example of such growth from cuttings involves the poet Alexander Pope, who begged a twig from a parcel tied with twigs sent from Spain to Lady Suffolk. This twig was planted and thrived, and legend has it that all of England's weeping willows are descended from this first one.[2]

Willows are often planted on the borders of streams so that their interlacing roots may protect the bank against the action of the water. Frequently the roots are much larger than the stem which grows from them.

Propagation

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Pests and diseases

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Species

About 350, including:
Salix acutifolia - Violet Willow
Salix alaxensis - Alaska Willow
Salix alba - White Willow
Salix alpina - Alpine Willow
Salix amygdaloides - Peachleaf Willow
Salix arbuscula - Mountain Willow
Salix arbusculoides - Littletree Willow
Salix arctica - Arctic Willow
Salix atrocinerea
Salix aurita - Eared Willow
Salix babylonica - Peking Willow
Salix bakko
Salix barrattiana - Barratt's Willow
Salix bebbiana - Beaked Willow
Salix boothii - Booth Willow
Salix bouffordii
Salix brachycarpa - Barren-ground Willow
Salix cacuminis
Salix canariensis
Salix candida - Sage Willow
Salix caprea - Goat Willow
Salix caroliniana - Coastal Plain Willow
Salix chaenomeloides
Salix chilensis
Salix cinerea - Grey Sallow
Salix cordata
Salix daphnoides
Salix discolor - Pussy Willow
Salix eastwoodiae - Eastwood's Willow
Salix eleagnos
Salix eriocarpa
Salix eriocephala - Heartleaf Willow
Salix exigua - Sandbar Willow
Salix fargesii
Salix foetida
Salix fragilis - Crack Willow
Salix futura
Salix geyeriana
Salix gilgiana
Salix glauca
Salix gooddingii - Goodding Willow
Salix gracilistyla
Salix hainanica - Hainan Willow
Salix hastata
Salix helvetica - Swiss Willow
Salix herbacea - Dwarf Willow
Salix hirsuta
Salix hookeriana - Hooker's Willow
Salix hultenii
Salix humboldtiana - Chile Willow
Salix humilis - Upland Willow
Salix integra
Salix interior
Salix irrorata
Salix japonica
Salix jessoensis
Salix koriyanagi
Salix kusanoi
Salix laevigata
Salix lanata - Woolly Willow
Salix lapponum - Downy Willow
Salix lasiandra - Pacific Willow
Salix lasiolepsis - Arroyo Willow
Salix lindleyana
Salix lucida - Shining Willow
Salix magnifica
Salix matsudana - Chinese Willow
Salix miyabeana
Salix mucronata
Salix myrtilloides - Swamp Willow
Salix myrsinifolia - Dark-leaved Willow
Salix myrsinites - Whortle-leaved Willow
Salix nakamurana
Salix nigra - Black Willow
Salix pedicellaris - Bog Willow
Salix pentandra - Bay Willow
Salix petiolaris - Slender Willow
Salix phylicifolia - Tea-leaved Willow
Salix planifolia- Planeleaf Willow
Salix polaris - Polar Willow
Salix pseudo-argentea
Salix purpurea - Purple Willow
Salix pyrifolia - Balsam Willow
Salix reinii
Salix repens - Creeping Willow
Salix reptans
Salix reticulata - Net-leaved Willow
Salix retusa
Salix rorida
Salix rosmarinifolia - Rosemary-leaved Willow
Salix rupifraga
Salix salicicola
Salix schwerinii
Salix scouleriana - Scouler's Willow
Salix sericea - Silky Willow
Salix serissaefolia
Salix serissima - Autumn Willow
Salix shiraii
Salix sieboldiana
Salix sitchensis
Salix subfragilis
Salix subopposita
Salix taraikensis
Salix taxifolia
Salix tetrasperma
Salix thorelii
Salix triandra - Almond Willow
Salix udensis
Salix viminalis - Common Osier
Salix vulpina
Salix waldsteiniana
Salix wallichiana
Salix wilmsii
Salix woodii
Salix yezoalpina
Salix yoshinoi

Hybrids:

Cultivars:


Read about Willow in the Standard Cyclopedia of Horticulture 


S. aglaia, Hort.-S. daphnoides.—S. amygdalina, Linn. (S. triandra. Linn.). Usually shrubby, to 12 ft.: branchlets glabrous, rarely slightly silky: lvs. lanceolate, glabrous, pale green or bluish below, to 5 in. long: fls. shortly before or with the lvs.; stamens 3; ovary long-stalked, glabrous. Eu.—S. Bakeri, Seemen, is probably a form of S. lasiolepis.—S. Bockii, Von Seemen. An ornamental dwarf species: lvs. oblong or oval, 1/4-1/2 in. long, mucronate, dark green and glabrescent above, silvery with silky appressed hairs beneath: aments 1-2 in. long, produced in Oct. and Nov. before the fall of the lvs. China.—S. chrysocoma. Dode, is a hybrid between S. babylonica and S. vitellina.—S. daphnoides, Vill. Ten to 20 ft. high: twigs violet: lvs. narrow-oblong or linear-lanceolate, very acuminate. 3-6 in. long.—S. Hankensonii, Dode. Apparently a natural hybrid between a species of the group of S. nigra and one of the group of S. babylonica.—S. heterandra, Dode. Possibly hybrid between a species of the S. purpurea group and one allied to S. pentandra. Shrub: lvs. lanceolate-obovate or narrowly lanceolate, 3—4 in. long, remotely serrate, glabrous, light green above, whitish- glaucous beneath: male aments about 1 3/4 in. long: Caucasus.—S. hypoleuca, Seemen. Shrub, to 10ft.: lvs. elliptic to lanceolate, acute, glabrous at maturity, glaucous below, 1-2 in. long: aments with the lvs. 1-2 in. long. Cent. W. China.—S. japonica, Thunb. (S. babylonica var. japonica, Anderss.). Shrub, to 6 ft.: lvs. ovate-oblong to lanceolate, remotely serrate, glabrous, grayish green beneath, to 3 in. long: aments slender, 2 1/2-3 1/2 in. long; ovary glabrous. Japan.— S.lasiolepis, Benth. Arroyo Willow. Shrub or tree, 8-25 ft. high: lvs. oblong, suborbicular, obovate or linear acute, obscurely serrulate, 1 1/2-5 in. long: aments appearing before the lvs., sessile, densely silky-tomentose in the bud, suberect: caps. glabrous or puberulent, short-pedicelled. Calif.—S. lispocladus, Dode. Lvs. ovate-lanceolate, about 2 1/2 in. long, serrate, light green and shining above, whitish glaucous beneath: male aments appearing late. Caucasus.— S. magnifica, Hemsl. Shrub, to 20 ft.: lvs. oval to obovate, shortly and obtusely acuminate, glabrous, pale beneath, to 8 in. long and to 5 in. wide; petiole purplish: staminate aments to 7 in., pistillate to 11 in. long. W. China. A remarkable willow, but tender N. J. H.S. 39. p. 137, fig. 148.—S. Matsudana, Koidsumi (S. babylonica var. pekinensis, Henry). Tree, to 40 ft.: branchlets ascending or pendulous, greenish: lvb. narrowly lanceolate, serrulate, glabrous, 2-4 in. long: aments with the lvs., about 1/2 in. long. N. E. Asia.—S. Medemii, Boiss., of the Armenia-Persia region is an upright species 12 ft. and more high with oblong somewhat serrate lvs. abruptly pointed.—S. Medwedewii, Dode. Shrub or small tree: lvs. very narrow, up to 4 in. long: female aments appearing late, cylindric, 1 1/4 in. long. Caucasus.—P. oxica, Dode. Lvs. large, glaucescent, giving the tree a bluish appearance. Cent. Asia.—S. persica, Boiss. Similar to P. babylonica. Trunk pale ashy gray or brownish: lvs. very shortly stalked, somewhat falcate, long-acuminate, serrulate. Persia.—S. Rehderiana, Schneid. Shrub, to 10 ft.: branchlets sparingly hairy or glabrous: lvs. lanceolate, crenulate, whitish and silky beneath, with yellow midrib, 2-5 in. long: aments precocious, about 1 in. long; anthers purple at first; ovaries glabrous. W. China. —S. renecia is a hybrid, of which S. cinerea is a parent.—S. Tominii, Dode. Tree with spreading branches: lvs. obovate to lanceolate, 3 1/3- 4 in. long or more, remotely serrate: male aments at first conical and rosy at apex, afterward ovate-cylindric, 3/4 in. long. W. Asia.—S. triandra, Linn.-S. amygdalina.—S. Wallichiana, Anderss. Shrub or small tree: lvs. ovate- to oblong-lanceolate, entire, silky beneath like the young branchlets, 2-3 in. long: staminate aments 1 in. long, pistillate 3—5 in.: caps slender, silky. Himayalas, Cent. and W. China.—S. zygostemon. Hook. f. & Thorn. Probably a natural hybrid between S. purpurea and S. Medemii.—S. Wentworthii, Hort., is described as a tall upright rapid-growing willow with bright red bark: botanical position to be determined.


The above text is from the Standard Cyclopedia of Horticulture. It may be out of date, but still contains valuable and interesting information which can be incorporated into the remainder of the article. Click on "Collapse" in the header to hide this text.


Gallery

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References

External links


  1. ↑ Mabberley, D.J. 1997. The Plant Book. Cambridge University Press #2: Cambridge.
  2. ↑ Hone, William (1826). "August 9". The Every-Day Book (Electronic Edition). Hone quotes "Martyn", and notes that Martyn in turn cites "the St. James's Chronicle, for August, 1801".
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