Difference between revisions of "Ulmus pumila"

From Gardenology.org - Plant Encyclopedia and Gardening Wiki
Jump to navigationJump to search
 
Line 1: Line 1:
 
{{SPlantbox
 
{{SPlantbox
 
|familia=Ulmaceae
 
|familia=Ulmaceae
|genus=Ulmus  
+
|genus=Ulmus
 
|species=pumila
 
|species=pumila
 
|common_name=Chinese elm, Siberian Elm
 
|common_name=Chinese elm, Siberian Elm
 
|name_ref=Flora - A Gardener's Encyclopedia
 
|name_ref=Flora - A Gardener's Encyclopedia
 +
|habit=tree
 
|Min ht box=20
 
|Min ht box=20
 
|Min ht metric=ft
 
|Min ht metric=ft
Line 15: Line 16:
 
|Max wd metric=ft
 
|Max wd metric=ft
 
|width_ref=Flora - A Gardener's Encyclopedia
 
|width_ref=Flora - A Gardener's Encyclopedia
 +
|lifespan=perennial
 
|exposure=sun
 
|exposure=sun
 
|sun_ref=Flora - A Gardener's Encyclopedia
 
|sun_ref=Flora - A Gardener's Encyclopedia
 +
|features=invasive
 
|Temp Metric=°F
 
|Temp Metric=°F
 
|min_zone=3
 
|min_zone=3
 
|usda_ref=Flora - A Gardener's Encyclopedia
 
|usda_ref=Flora - A Gardener's Encyclopedia
 
|max_zone=9
 
|max_zone=9
|image=Upload.png
+
|image=Ulmus pumila.jpg
|image_width=240
+
|image_width=180
}}
 
__NOTOC__{{Plantbox
 
| latin_name = ''LATINNAME''  <!--- replace LATINNAME with the actual latin name -->
 
| common_names =    <!--- if multiple, list all, if none, leave blank -->
 
| growth_habit = ?  <!--- tree, shrub, herbaceous, vine, etc -->
 
| high = ?  <!--- 1m (3 ft) -->
 
| wide =    <!--- 65cm (25 inches) -->
 
| origin = ?  <!--- Mexico, S America, S Europe, garden, etc -->
 
| poisonous =    <!--- indicate parts of plants which are known/thought to be poisonous -->
 
| lifespan =    <!--- perennial, annual, biennial -->
 
| exposure = ?  <!--- full sun, part-sun, shade -->
 
| water = ?  <!--- frequent, regular, drought tolerant -->
 
| features =    <!--- flowers, fragrance, fruit, edible, naturalizes, invasive -->
 
| hardiness =    <!--- frost sensitive, hardy, 5°C (40°F), etc -->
 
| bloom =    <!--- seasons which the plant blooms, if it is grown for its flowers -->
 
| usda_zones = ?  <!--- eg. 8-11 -->
 
| sunset_zones =    <!--- eg. 8, 9, 12-24, not available -->
 
| color = IndianRed
 
| image = Upload.png  <!--- Freesia.jpg -->
 
| image_width = 240px    <!--- leave as 240px if horizontal orientation photo, or change to 180px if vertical -->
 
| image_caption =    <!--- eg. Cultivated freesias -->
 
| familia =    <!--- Family -->
 
| genus =
 
| species =
 
| subspecies =    <!--- If this is a page for a subspecies, most are just listed on the species page -->
 
| cultivar =    <!--- If this is a page for a Variety/Cultivar, usually comes after "var." or is in 'single quotes' -->
 
 
}}
 
}}
 +
'''''Ulmus pumila''''' <small>L.</small>, the '''Siberian Elm''', is native to [[Turkestan]], eastern [[Siberia]], [[Mongolia]], [[Xizang]] ([[Tibet]]), northern [[China]], [[India]] (northern Kashmir) and [[Korea]] <ref name=Fu>Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) ''Flora of China'', Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA. [http://flora.huh.harvard.edu/china/PDF/PDF05/Ulmus.pdf] </ref>. It is also known as the '''Asiatic Elm, Dwarf Elm''' and (erroneously) '''Chinese Elm'''. ''U. pumila'' has been widely cultivated throughout [[Asia]], [[North America]] and, to a lesser extent, southern [[Europe]].
 +
 +
The Siberian Elm is usually a small to medium-sized, often bushy, [[tree]] growing to 10 - 20 m tall, with a trunk up to 80&nbsp;cm [[diameter at breast height|d.b.h]]. The [[leaf|leaves]] are [[deciduous]] in cold areas, but [[evergreen|semi-evergreen]] in warmer climates, < 7&nbsp;cm long and < 3&nbsp;cm broad, with an oblique base and a coarsely serrated margin, changing from dark green to yellow in autumn. The wind-dispersed fruit develops in a flat, oval membranous wing ([[Samara (fruit)|samara]]) 1 - 1.5&nbsp;cm long and notched at the outer end <ref name=Elwes>Elwes, H. J. & Henry, A. (1913). ''The Trees of Great Britain & Ireland''. Vol. VII. pp 1848&ndash;1929. Private publication. [http://fax.libs.uga.edu/QK488xE4/1f/trees_of_britain_and_ireland_vol_7.pdf] </ref> <ref name=Rushforth>Rushforth, K. (1999). ''Trees''. Collins.</ref> <ref name=Huxley>Huxley, A. (1992). ''The New RHS Dictionary of Gardening''. Macmillan.</ref>. The tree is short-lived in temperate climates, rarely reaching more than 60 years of age, but in its native environment may live to between 100 and 150 years [http://www.northern.edu/natsource/TREESA1/Siberi1.htm]. 
 +
 
{{Inc|
 
{{Inc|
<!--- ******************************************************* -->
+
Ulmus pumila, Linn. (U. microphylla, Pers. U. sibirica, Hort.). Small tree or shrub, with slender pubescent, sometimes pendulous branches: lvs. oval-elliptic to elliptic-lanceolate, short-petioled, acute, firm, dark green and smooth above, pubescent when young beneath, 3/4 - 3 in. long: fls. short-pedicelled; stamens 4-5, with violet anthers: fr. obovate, with the nutlet somewhat above the middle, incision at the apex reaching about half-way to the nutlet. Turkestan to Siberia and N. China.—A graceful small hardy tree. Var. arborea, Litwinow (U. pinnata-ramosa, Dieck. U. turkestanica, Regel). Tree with long, pinnately branched shoots pubescent when young: lvs. oblong-lanceolate, 1 – 2 1/2 in. long; petioles pubescent at first. Var. pendula, Hort. (U. parvifolia pendula, Hort. Planera repens, Hort.), has slender more pendulous branches.
Ulmus pumila, Linn. (U. microphylla, Pers. U. sibirica, Hort.). Small tree or shrub, with slender pubescent, sometimes pendulous branches: lvs. oval-elliptic to elliptic-lanceolate, short-petioled, acute, firm, dark green and smooth above, pubescent when young beneath, 3/4 - 3 in. long: fls. short-pedicelled; stamens 4-5, with violet anthers: fr. obovate, with the nutlet somewhat above the middle, incision at the apex reaching about half-way to the nutlet. Turkestan to Siberia and N. China. Gn. 65, p. 133.—A graceful small hardy tree. Var. arborea, Litwinow (U. pinnata-ramosa, Dieck. U. turkestanica, Regel). Tree with long, pinnately branched shoots pubescent when young: lvs. oblong-lanceolate, 1 – 2 1/2 in. long; petioles pubescent at first. Var. pendula, Hort. (U. parvifolia pendula, Hort. Planera repens, Hort.), has slender more pendulous branches.
 
 
{{SCH}}
 
{{SCH}}
 
}}
 
}}
 +
 +
As an [[ornamental]] ''U. pumila'' is a very poor tree, tending to be short-lived, with brittle wood and poor crown shape, but has nevertheless enjoyed some popularity owing to its rapid growth and provision of shade. The Siberian Elm has been described by Prof. [[Michael Dirr]] as "one of, if not ''the'', world's worst trees...a poor ornamental that does not deserve to be planted anywhere" <ref name=Dirr>Dirr, M. (1975). ''Manual of Woody Landscape Plants''. Stipes Publishing LLC. Champaign, Illinois.</ref>. Yet in the USA during the 1950s, the tree was also widely promoted as a fast growing hedging substitute for [[Privet]], and as a consequence is now commonly found in nearly all states <ref name=Klingaman>Klingaman, G. (1999). Plant of the Week: Siberian Elm. ''Extension News'', University of Arkansas, Division of Agriculture.</ref>. In the [[UK]], its popularity has been almost exclusively as a [[bonsai]] subject, and mature trees are largely restricted to arboreta. Introduced into [[Spain]] in the 16th century, and later [[Italy]], it has naturally hybridized with the [[Field Elm]] ''U. minor''. In Italy it was widely used in viniculture, notably in the [[Po River|Po]] valley, to support vines until the 1950s, when the demands of mechanization made it unsuitable.
 +
 +
;Invasiveness
 +
In North America it has become an [[invasive species]] from central [[Mexico]] <ref name=Todzia>Todzia, C. A. & Panero, J. L. (2006). A new species of Ulmus (Ulmaceae) from southern Mexico and a synopsis of the species in Mexico. ''Brittonia'', Vol 50, (3): 346</ref> [http://www.jstor.org/stable/2807778?seq=1] to [[Ontario]].  It is found in abundance along railroads and in abandoned lots and on disturbed ground.  The gravel along railroad beds provides ideal conditions for its growth: well-drained, nutrient poor soil, and high light conditions, and these beds provide corridors which facilitate its spread.  Owing to its high sunlight requirements, it seldom invades mature forests, and is primarily a problem in cities and open areas <ref name=National>National Audubon Society (2002). ''Field Guide to North American Trees'', Western Region, p. 419-420</ref>. In [[South America]], the tree has spread across much of the Argentinian [[pampas]] <ref name=Villamil>Villamil, C. B., Zalba, S. M. ''Red de información sobre especies exóticas invasoras - I3N-Argentina'' Universidad Nacional del Sur
 +
Bahía Blanca, Argentina</ref>.
  
 
==Cultivation==
 
==Cultivation==
{{edit-cult}}<!--- Type cultivation info below this line, then delete this entire line -->
+
The species has a high sunlight requirement and is not shade-tolerant; with adequate light it exhibits rapid growth.  The tree is also fairly intolerant of wet ground conditions, growing better on well-drained soils. While it is very resistant to drought and severe cold, and able to grow on poor soils, its short period of [[dormancy]], flowering early in spring followed by continuous growth until the first frosts of autumn, <ref name=Geng>Geng, M. A. (1989). A provenance test with elm (Ulmus pumila L.) in China. ''Silvae Genetica'' 32 (2), 37-44.</ref> renders it vulnerable to frost damage.
  
 
===Propagation===
 
===Propagation===
{{edit-prop}}<!--- Type propagation info below this line, then delete this entire line -->
+
 
  
 
===Pests and diseases===
 
===Pests and diseases===
{{edit-pests}}<!--- Type pest/disease info below this line, then delete this entire line -->
+
The tree has considerable variability in resistance to [[Dutch elm disease]].<ref name=Smalley>Smalley, E. & Guries, R. P. (1993). Breeding elms for resistance to Dutch elm disease. ''Annual Review of Phytopathology'', 31, 325-352</ref> Moreover, like many other elms in North America, it is highly susceptible to damage from many insects and parasites, including the elm leaf beetle ''[[Xanthogaleruca luteola]]'',<ref name=Miller>Miller, F. and Ware, G. (2001). Resistance of Temperate Chinese Elms (Ulmuss spp.) to Feeding of the Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae). ''Journal of Economic Entomology'' 94 (1): 162-166. 2001. Entom. Soc.of America.</ref><ref>[http://www.sunshinenursery.com/survey.htm]</ref> [[powdery mildew]], cankers, [[aphids]], and [[leaf spot]]. In trials in Italy, the species was also found to have a slight to moderate susceptibility to [[Elm Yellows]].<ref name=Mittempergher>Mittempergher, L. & Santini, A. (2004). The History of Elm Breeding. ''Invest. Agrar.: Sist Recur For. 2004 13 (1), 161-177.</ref>  However, ''U. pumila'' is the most resistant of all the elms to [[verticillium wilt]].<ref name=Pegg>Pegg, G. F. & Brady, B. L. (2002). ''Verticillium Wilts''. CABI Publishing. [[ISBN 0-85199-529-2]]</ref>
  
==Species==
+
==Varieties==
<!--  This section should be renamed Cultivars if it appears on a page for a species (rather than genus), or perhaps Varieties if there is a mix of cultivars, species, hybrids, etc    -->
+
One variety is recognized: [[Ulmus pumila var. arborea|var. ''arborea'']] <small>Litv.</small>.
 +
==Cultivars==
 +
Valued for the high resistance of some clones to [[Dutch elm disease]], over a dozen selections have been made to produce hardy ornamental cultivars, although several may no longer be in cultivation: 
 +
*[[Ulmus 'Ansaloni'|Ansaloni]], [[Ulmus 'Aurescens'|Aurescens]], [[Ulmus 'Chinkota'|Chinkota]], [[Ulmus 'Dropmore'|Dropmore]], [[Ulmus 'Green King'|Green King]], [[Ulmus 'Hansen'|Hansen]], [[Ulmus 'Harbin'|Harbin]], [[Ulmus 'Manchu'|Manchu]], [[Ulmus 'Mr. Buzz'|Mr. Buzz]], [[Ulmus 'Park Royal'|Park Royal]], [[Ulmus 'Pendula' (Siberian elm cultivar)|Pendula]], [[Ulmus 'Pyramidalis Fiorei'|Pyramidalis Fiorei]], [[Ulmus 'Variegata' (Siberian elm cultivar)|Variegata]]
 +
==Hybrid cultivars==
 +
The species has been widely hybridized in the [[USA]] and [[Italy]] to create robust trees of more native appearance with high levels of resistance to Dutch elm disease:
 +
*[[Arno (elm hybrid)|Arno]], [[Cathedral (elm hybrid)|Cathedral]], [[Coolshade (elm hybrid)|Coolshade]], [[Fiorente (elm hybrid)|Fiorente]], [[Homestead (elm hybrid)|Homestead]], [[Lincoln (elm cultivar)|Lincoln]], [[Ulmus 'Morton Plainsman'|Morton Plainsman]], [[Ulmus 'Morton Stalwart'|Morton Stalwart]], [[Ulmus 'New Horizon'|New Horizon]], [[Plinio (elm cultivar)|Plinio]], [[Regal (elm hybrid)|Regal]], [[Rosehill (elm hybrid)|Rosehill]], [[San Zanobi (elm cultivar)|San Zanobi]], [[Urban (elm cultivar)|Urban]], [[Willis (elm hybrid)|Willis]].
 +
Also ''U.'' '260' (''Ulmus × hollandica'' 'Vegeta' × ''Ulmus pumila'') raised at [[Wageningen]] but never commercially released; a few specimens survive as part of the [[Brighton & Hove]] CC [[NCCPG]] Elm Collection at Happy Valley Park, [[Woodingdean]]; Crespin Way, Hollingdean (10 trees), The Highway, Moulsecoomb (1 tree) and Royal Pavilion Gardens (1 tree).
  
 
==Gallery==
 
==Gallery==
{{photo-sources}}<!-- remove this line if there are already 3 or more photos in the gallery  -->
 
  
<gallery>
+
<gallery perrow=5>
Image:Upload.png| photo 1
+
File:Ulmus pumila1.jpg
Image:Upload.png| photo 2
+
File:Siberian Elm (Ulmus pumila) bark detail.jpg
Image:Upload.png| photo 3
+
File:비술나무 잎가지.JPG
 +
File:Ulmus pumila 20070415.jpg
 
</gallery>
 
</gallery>
  
 
==References==
 
==References==
*[[Standard Cyclopedia of Horticulture]], by L. H. Bailey, MacMillan Co., 1963
+
<references/>
 
<!--- xxxxx  *Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881925381  -->
 
<!--- xxxxx  *Flora: The Gardener's Bible, by Sean Hogan. Global Book Publishing, 2003. ISBN 0881925381  -->
 
<!--- xxxxx  *American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432  -->
 
<!--- xxxxx  *American Horticultural Society: A-Z Encyclopedia of Garden Plants, by Christopher Brickell, Judith D. Zuk. 1996. ISBN 0789419432  -->
Line 87: Line 80:
  
 
{{stub}}
 
{{stub}}
[[Category:Categorize]]
+
__NOTOC__
 
 
<!--  in order to add all the proper categories, go to http://www.plants.am/wiki/Plant_Categories and copy/paste the contents of the page here, and then follow the easy instructions!    -->
 

Latest revision as of 18:10, 5 May 2010


Ulmus pumila.jpg


Plant Characteristics
Habit   tree

Height: 20 ft"ft" can not be assigned to a declared number type with value 20. to 35 ft"ft" can not be assigned to a declared number type with value 35.
Width: 20 ft"ft" can not be assigned to a declared number type with value 20. to 30 ft"ft" can not be assigned to a declared number type with value 30.
Lifespan: perennial
Cultivation
Exposure: sun
Features: invasive
USDA Zones: 3 to 9
Scientific Names

Ulmaceae >

Ulmus >

pumila >


Ulmus pumila L., the Siberian Elm, is native to Turkestan, eastern Siberia, Mongolia, Xizang (Tibet), northern China, India (northern Kashmir) and Korea [1]. It is also known as the Asiatic Elm, Dwarf Elm and (erroneously) Chinese Elm. U. pumila has been widely cultivated throughout Asia, North America and, to a lesser extent, southern Europe.

The Siberian Elm is usually a small to medium-sized, often bushy, tree growing to 10 - 20 m tall, with a trunk up to 80 cm d.b.h. The leaves are deciduous in cold areas, but semi-evergreen in warmer climates, < 7 cm long and < 3 cm broad, with an oblique base and a coarsely serrated margin, changing from dark green to yellow in autumn. The wind-dispersed fruit develops in a flat, oval membranous wing (samara) 1 - 1.5 cm long and notched at the outer end [2] [3] [4]. The tree is short-lived in temperate climates, rarely reaching more than 60 years of age, but in its native environment may live to between 100 and 150 years [4].


Read about Ulmus pumila in the Standard Cyclopedia of Horticulture 

Ulmus pumila, Linn. (U. microphylla, Pers. U. sibirica, Hort.). Small tree or shrub, with slender pubescent, sometimes pendulous branches: lvs. oval-elliptic to elliptic-lanceolate, short-petioled, acute, firm, dark green and smooth above, pubescent when young beneath, 3/4 - 3 in. long: fls. short-pedicelled; stamens 4-5, with violet anthers: fr. obovate, with the nutlet somewhat above the middle, incision at the apex reaching about half-way to the nutlet. Turkestan to Siberia and N. China.—A graceful small hardy tree. Var. arborea, Litwinow (U. pinnata-ramosa, Dieck. U. turkestanica, Regel). Tree with long, pinnately branched shoots pubescent when young: lvs. oblong-lanceolate, 1 – 2 1/2 in. long; petioles pubescent at first. Var. pendula, Hort. (U. parvifolia pendula, Hort. Planera repens, Hort.), has slender more pendulous branches. CH


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.


As an ornamental U. pumila is a very poor tree, tending to be short-lived, with brittle wood and poor crown shape, but has nevertheless enjoyed some popularity owing to its rapid growth and provision of shade. The Siberian Elm has been described by Prof. Michael Dirr as "one of, if not the, world's worst trees...a poor ornamental that does not deserve to be planted anywhere" [5]. Yet in the USA during the 1950s, the tree was also widely promoted as a fast growing hedging substitute for Privet, and as a consequence is now commonly found in nearly all states [6]. In the UK, its popularity has been almost exclusively as a bonsai subject, and mature trees are largely restricted to arboreta. Introduced into Spain in the 16th century, and later Italy, it has naturally hybridized with the Field Elm U. minor. In Italy it was widely used in viniculture, notably in the Po valley, to support vines until the 1950s, when the demands of mechanization made it unsuitable.

Invasiveness

In North America it has become an invasive species from central Mexico [7] [5] to Ontario. It is found in abundance along railroads and in abandoned lots and on disturbed ground. The gravel along railroad beds provides ideal conditions for its growth: well-drained, nutrient poor soil, and high light conditions, and these beds provide corridors which facilitate its spread. Owing to its high sunlight requirements, it seldom invades mature forests, and is primarily a problem in cities and open areas [8]. In South America, the tree has spread across much of the Argentinian pampas [9].

Cultivation

The species has a high sunlight requirement and is not shade-tolerant; with adequate light it exhibits rapid growth. The tree is also fairly intolerant of wet ground conditions, growing better on well-drained soils. While it is very resistant to drought and severe cold, and able to grow on poor soils, its short period of dormancy, flowering early in spring followed by continuous growth until the first frosts of autumn, [10] renders it vulnerable to frost damage.

Propagation

Pests and diseases

The tree has considerable variability in resistance to Dutch elm disease.[11] Moreover, like many other elms in North America, it is highly susceptible to damage from many insects and parasites, including the elm leaf beetle Xanthogaleruca luteola,[12][13] powdery mildew, cankers, aphids, and leaf spot. In trials in Italy, the species was also found to have a slight to moderate susceptibility to Elm Yellows.[14] However, U. pumila is the most resistant of all the elms to verticillium wilt.[15]

Varieties

One variety is recognized: var. arborea Litv..

Cultivars

Valued for the high resistance of some clones to Dutch elm disease, over a dozen selections have been made to produce hardy ornamental cultivars, although several may no longer be in cultivation:

Hybrid cultivars

The species has been widely hybridized in the USA and Italy to create robust trees of more native appearance with high levels of resistance to Dutch elm disease:

Also U. '260' (Ulmus × hollandica 'Vegeta' × Ulmus pumila) raised at Wageningen but never commercially released; a few specimens survive as part of the Brighton & Hove CC NCCPG Elm Collection at Happy Valley Park, Woodingdean; Crespin Way, Hollingdean (10 trees), The Highway, Moulsecoomb (1 tree) and Royal Pavilion Gardens (1 tree).

Gallery

References

  1. Fu, L., Xin, Y. & Whittemore, A. (2002). Ulmaceae, in Wu, Z. & Raven, P. (eds) Flora of China, Vol. 5 (Ulmaceae through Basellaceae). Science Press, Beijing, and Missouri Botanical Garden Press, St. Louis, USA. [1]
  2. Elwes, H. J. & Henry, A. (1913). The Trees of Great Britain & Ireland. Vol. VII. pp 1848–1929. Private publication. [2]
  3. Rushforth, K. (1999). Trees. Collins.
  4. Huxley, A. (1992). The New RHS Dictionary of Gardening. Macmillan.
  5. Dirr, M. (1975). Manual of Woody Landscape Plants. Stipes Publishing LLC. Champaign, Illinois.
  6. Klingaman, G. (1999). Plant of the Week: Siberian Elm. Extension News, University of Arkansas, Division of Agriculture.
  7. Todzia, C. A. & Panero, J. L. (2006). A new species of Ulmus (Ulmaceae) from southern Mexico and a synopsis of the species in Mexico. Brittonia, Vol 50, (3): 346
  8. National Audubon Society (2002). Field Guide to North American Trees, Western Region, p. 419-420
  9. Villamil, C. B., Zalba, S. M. Red de información sobre especies exóticas invasoras - I3N-Argentina Universidad Nacional del Sur Bahía Blanca, Argentina
  10. Geng, M. A. (1989). A provenance test with elm (Ulmus pumila L.) in China. Silvae Genetica 32 (2), 37-44.
  11. Smalley, E. & Guries, R. P. (1993). Breeding elms for resistance to Dutch elm disease. Annual Review of Phytopathology, 31, 325-352
  12. Miller, F. and Ware, G. (2001). Resistance of Temperate Chinese Elms (Ulmuss spp.) to Feeding of the Adult Elm Leaf Beetle (Coleoptera: Chrysomelidae). Journal of Economic Entomology 94 (1): 162-166. 2001. Entom. Soc.of America.
  13. [3]
  14. Mittempergher, L. & Santini, A. (2004). The History of Elm Breeding. Invest. Agrar.: Sist Recur For. 2004 13 (1), 161-177.
  15. Pegg, G. F. & Brady, B. L. (2002). Verticillium Wilts. CABI Publishing. ISBN 0-85199-529-2

External links