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{{Taxobox
{{Taxobox
| color = lightgreen
| color = lightgreen
| name = ''Pachypodium''
| name = ''Pachypodium brevicaule''
| image = Pachypodium_lamerei.PNG
| image = Pachypodium brevicaule 1.jpg
| image_width = 250px
| image_width = 250px
| regnum = [[Plantae]]
| regnum = [[Plantae]]
| divisio = [[Flowering plant|Magnoliophyta]]
| divisio = [[Flowering plant|Magnoliophyta]]
| ordo = [[Gentianales]]
| ordo = [[Gentianales]]
| familia = [[Apocynaceae]]
| familia = [[Apocynaceae]]
| genus = '''''Pachypodium'''''
| genus = ''[[Pachypodium]]''
| species = '''''P. brevicaule'''''
| binomial = ''Pachypodium brevicaule''
| binomial_authority = Baker
''[[Pachypodium ambongense]]''<br />
''[[Pachypodium baronii]]''<br />
''[[Pachypodium bispinosum]]''<br />
''[[Pachypodium brevicaule]]''<br />
}}
}}
'''''Pachypodium''''' is a [[plant]] [[genus]] that belongs to the dogbane [[family (biology)|family]], [[Apocynaceae]]. ''Pachypodium'' comes from [[Greek language|Greek]] ''pachy'' (thick) and ''podium'' (foot), hence meaning ''thick-footed''.
'''''Pachypodium brevicaule''''' is a species of plant that belongs to the dogbane family [[Apocynaceae]], which is now amplified by the inclusion of the milkweed family [[Asclepiadaceae]] -- ''an important union to botanists and horticulturalists interested in the alliance [[succulent]]s''.
==Genus characteristics==
===[[range (biology)|Distribution]]===
This plant is native to [[Madagascar]], from the south of Antananarivo to the Itremo Mountains.
===Habit===
A flattened, tuberous, [[cactus]]-like plant with a very low [[trunk]] and a very wide, exaggerated diameter without substantive branching whatsoever with exception to several extremely short flattened "branch"-like [[nodes]] or [[rosettes]] of [[leaf|leaves]].
===[[Ecology]]===
''Pachypodium brevicaule'' Baker grows in open, [[deciduous]] Western [[forest]] of Madagascar in full sun on [[sandstone]], rarely on [[granite]], in [[crevices]] between outcrops of [[quartzite]]. With a [[pH|pH. Level]] varying from 3.5 to 4.5, it is strictly adapted to growing in [[acid]] [[Substrate (biology)|substrate]]s. (That strictness to acidity seemingly has implications to its [[cultivation]].) It is found in the [[evergreen]] [[Sclerophyllous]] (''[[Uapaca]]'') [[woodland]] or [[savanna]] zones dominated by scattered [[woody]] plants. It grows at [[altitude]]s of 1250-1900 (2000 m) m.
Associated plant [[species]], site indicators, include ''[[Pachypodium densiflorum]]'', ''[[Pachypodium eburneum|P. eburneum]]'' ([[Apocynaceae]]), ''[[Aloe]] compressa,'' ''A. capitata,'' ([[Asphodelaceae]]), ''[[Euphorbia]] quartzicola'' ([[Euphorbiaceae]]), ([[Orchidaceae]]), ([[Graminaea]]), ([[Moss|Bryophyta]]), and [[Lichen]]es.
It occurs in a region that receives an annual [[rainfall]] of 1354 mm with a number of [[drought|5 dry months]]. Average monthly [[temperature]]s varies from 9°C to 17°C. The yearly average temperature is higher; however, at 13°C to 18.4°C.
===[[Vernacular]] [[Malagasy]] Common Name===
"Tsimondrimondry" ([[Merina]]); "Kimondromondro" ([[Betsileo]])
==[[Morphology (biology)|Morphology]]==
===Habit===
''Pachypodium brevicaule'' is unique to the [[genus]] in habit. It is considered a [[dwarf]] plant. It takes on a broad flattenened tuberous, cactus-like habit that has a very short [[trunk]] measuring 2 to 8 cm high and an exaggerated diameter that can reach 10 to 40 cm. When in [[flower]] the plant gains stature by reaching a height of 25 cm. ''Pachypodium brevicaule'' Baker barely, if all, "branches." Rather it seems to form protruding [[nodes]] or [[rosettes]] of leaves that ranch from 1 to 4 cm in length and 2 to 4 cm in width. In the "Botanical Key for the Genus ''Pachypodium''," the character "without branches or branchlets" is a distinguishing [[Morphology (biology)|morphological]] character to the species ''Pachypodium brevicaule'''s definition.
The [[bark]] is colored pale grey and is sometimes shiny. It has a smooth texture. The bark is about 2 to 4 mm thick, with the [[wood]] being greenish. The "branches" or, better said, nodes of rosettes of leaves, when fresh, have paired, rather soft, curved [[spine (biology)|spine]]s at their [[apex|apices]], measuring 2 to 9 mm long by 1 to 1.5 mm at the base. They are pale grey to pale brown. When young, they are [[pubescent]] and more or less flat.
The [[Morphology (biology)|morphology]] of the [[genus]] ''Pachypodium'' varies significantly both within and between species and is highly responsive to its immediate surrounding [[microenvironment]]. ''Pachypodium'' do not overly respond morphologically to larger vegetative zones. For example, ''Pachypodium'' can sometimes occur in prehumid vegetative zones where a taxon might find a suitable habitat on a rocky, sunny [[inselberg]] jutting above the humid canopy of the forest.
===[[Leaves]]===
''Pachypodium brevicaule'' has leaves that are confined to the apices of the branches or nodes and rosettes. The leaves are [[sessile]], without a [[Plant stem|stem]], [[Petiole (botany)|petiolate]]--''with a [[stalk (botany)|stalk]]''--[[peduncle]]--''the main axis of the [[inflorescence]]''--or [[pedicel]]--''the stalk of a single flower''--or it is shortly petiolate--''having a stalk.'' If it has a stalk, the [[Petiole (botany)|petiole]] measures up to 2 mm long. It is sparsely pubescent, fuzzy.
The leaf blade is [[herbaceous]], not woody-like, and [[glaucous]], covered in a very fine [[bloom]] or a fine powdery layer, when fresh and papery when dried. The blade is shaped [[ovate]], broad and rounded at the base and tapering toward the end, to [[obovate]], egg-shaped and flat with the narrow end attached to the stalk. It measures 11 to 30 mm in length by 6 to 12 mm in width. The apex of the blade is [[acuminate]], narrowing to a slender point. The base is blunt or rounded. The blade of ''Pachypodium brevicaule'' Baker is [[glabrous]], smooth, to sparsely pubescent, slightly hairy, on both sides, with impressed [[venation]] above, and with midrib and secondary veins prominent beneath. There are 15-30 pairs of secondary veins, which are straight at the base, upcurved at the apex, and forming an angle of 45-85° with the costa, or the midrib of a leaf. The [[tertiary]], third-level, venation are [[reticulate]], forming a web or a network like pattern.
===[[Inflorescence]]===
The inflorescence of ''Pachypodium brevicaule'' is [[sessile]], with a stalk, or [[pedunculate]], with the main axial stem to an inflorescence. It can be congested with up to 7 flowers where the inflorescence measures 2.5 to 15 cm in length by 2 to 6.5 cm in width. The peduncle, itself, is glaucous and covered in a fine bloom. It takes the shape of a [[terete]], an elongated cylindrical form that is round in cross-section. The terete measures roughly up to 120 mm in length by 2 to 4 mm in width. The degree of pubescent varies on the peduncle from sparsely to fully hairy, pubescent. The pedicels, the stalk of a single flower, measures up to 8 mm long and is hairy, pubescent.
The [[bract]]s, modified leaves at the base of a pedicel of a flower, a peduncle, or a branch, are longer than the pedicels on ''Pachypodium brevicaule'' Baker. They are narrowly oblong, having a somewhat elongated form with approximately parallel sides, to obovate, egg-shaped and flat with the narrow end attached to the stalk. The bracts measure from 5 to 13 mm long by 1.5 to 3 mm wide.. At their apex, they are [[acuminate]], tapering gradually to a sharp point, or [[Angle#Types_of_angles|acute]], having a sharp point or tip. On the outside, the bracts are fully pubescent, hairy to slightly so. Inside they are less so.
=====[[Flower]]s=====
The sepals of ''Pachypodium brevicaule's'' flower are glaucous, having a fine bloom over the surface. This bloom covers the [[anatomical terms of location|basal]] part of the [[corolla tube]], the [[petals]] of a flower considered as a group or unit and usually of a color other than green, or the inner whorl of the [[perianth]] shaped like a tube. The sepals are [[connate]], united to a structure of the same kind, i.e. other sepals, at the base for about 0.5 mm. They are narrowly ovate, broad and rounded at the base and tapering toward the end, or narrowly oblong, having a somewhat narrowly elongated form with approximately parallel sides. The sepals measure 6 to 11 mm long by 2 to 3 mm wide. At the apex, they are acuminate, tapering gradually to a sharp point, or acute, having a sharp point or tip. Outside the sepals are often glabrous and smooth; whereas inside in the lower part and near the apex, they are slightly pubescent, hairy.
===Adaptive Features===
=====[[Corolla]]=====
The corolla, the inner whorl of the perianth, is bright yellow. It measures 17 to 25 mm long in the mature [[bud]] and forms a comparatively wide broadly [[ovoid]], shaped like an egg, ovate, head measuring 7 to 11 mm long by 5 to 8 mm wide. The apex of the bud is [[obtuse]], having a blunt or rounded tip. Overall the bud is pubescent outside. The [[corolla lobes]] are not as hairy; however. Especially where the lobes and tubes are covered in bud, the surface is glabrous. The pubescent belt inside the corolla tube is 2 mm above to 1 mm below where the [[stamens]] are inserted, not emerging beyond the corolla tube. Otherwise the corolla tube is glabrous and smooth. It is shaped like a funnel, [[infundibuliform]], at 12 to 18 mm long (1.63 times as large as the calyx and 1.05 to 1.36 times as long as the lopes) The basal of the corolla tube is almost cylindrical. It is 2 to 3 mm long by 2 to 2.5 mm wide above the base (0.15 to 0.18 times the entire length of the entire tube.) The upper part of the corolla tube is almost cylindrical. Yet it widens at the throat altering the cylindrical form. The upper part measures 10 to 15 mm long by 5 to 5.7 mm wide at the mouth. The lobes are obliquely obovate, having sides of unequal length or form, which are egg-shaped and flat with the narrow end attached to the [[stalk (botany)|stalk]]. At their apex, the lobe of ''Pachypodium brevicaule'' Baker are rounded. They measure 9 to 18 mm in length by 8.5 to 14 mm in width. (That is, in proportion, the lobes are 0.73 to 0.94 times as long as the corolla tube and 1.1 to 1.3 times as long as they are wide.)
=====Stamens=====
The stamens of ''Pachypodium brevicaule'', with an apex of 4 to 9 mm below the [[mouth]] of the corolla tube, are inserted, meaning they do not extent beyond the corolla tube or mouth of the flower. They measure from the base 3.5 to 4 mm. (Proportionally they are 0.22-0.29 of the length of the corolla tube.) The stamens are the "male reproductive" organ of an angiospermous flowering plant.
The anthers, the part of the stamen, typically on top, which bears the pollen, commonly consisting of (1) two of four [[theca]]e, which contain the [[pollen]] and (2) a [[infertility|sterile]] region in between the connective that is very narrowly triangular. The anthers range in size for ''Pachypodium brevicaule'' from 4.7 to 5.2 mm long by 0.7 to 0.9 mm wide. (Proportionally, that is, they are 5.22 to 7.14 times as long as wide.) Inside, the anthers are pubescent and hairy at the base of the connective, the part of tissue in a stamen that separates the two thecae of an anther. As well, it is pubescent just below where stamens cohere with the [[pistil head]], the fertile region of the flower.
''Pachypodium'' trunks and branches are anormally thickened with water-storing tissue. Plants must relie on the food and water stored in their thickened trunks during seasonal or intermittent drought when leaves have been shed and no water is available from the substrate. In addition to the lower surface-to-volume ratio which aides in water retention, the thickened trunks and branches can also possess photosyntehtic surface tissue to allow nutrient synthesis even when leaves are not present.
=====[[Pistil]]=====
Composing the female reproductive organ, the [[pistil]] varies in length from 4.8 to 6.5 mm.
Pubescent and hairy, the [[ovary (plants)|ovary]] measures ovary 1.5 to 1.9 mm long (x) by 1.3 to 1.6 mm wide (y) by 1.2 mm high (z). The [[disk]] in a pistil is the slightly thickened, or otherwise distinguished region, around the [[carpel|style]] in certain flowers that secret [[nectar]]. The disks of ''Pachypodium brevicaule'' Baker number 5 broad ovate glands that are broad and rounded at the base and tapering toward their end. These glands, for which either 2 or 2 pair can be partly fused together, are about half as long as the ovary. (Proportionally that 0.5 times 1.5 to 1.9 mm.).
The often cylindrical stalk-like portion connecting the [[carpel|stigma]] with the [[carpel]] or ovary, the style is slightly pubescent and hairy at the base for the [[taxon]]. The stigma is the top-most receptive region of the style, which often divided into [[stigma-lobes]] that are commonly wet by a sticky exudate that helps captures and nourish pollen grains. The carpel, furthermore, is the female organ of the angiospermous flower that consists of a modified leaf that contains the ovules. Several carpels can be fused together to from a compound ovary.
The concept of "[[micro]]-[[endemic (ecology)|endemism]]" plays an important role in this relationship between adaptation mechanisms and speciation. It suggests a certain small scale "nativeness" by virtue of originating or occurring naturally in a particular [[place]] or [[location (geography)|location]]. The [[landscape]] of Madagascar is a perfect example of "micro-endemism" for species of ''Pachypodium'' and other taxa. Three factors can be seen to attribute speciation, or the occurrence of species diversity, via adaptive mechanisms to accelerated [[evolution]] as it occurs within the xeric landscape and [[climate]].
The slightly pubescent style for ''Pachypodium brevicaule'' measures 2.6 to 3.6 mm long. The pistil head, the separate part attached to the style, is 0.71 to 1.0 mm high. It composition is complex. Its basal part is 0.4 to 0.6 mm long by 0.4 to 0.6 mm wide. The central part is ring-shaped at 0.15 to 0.2 mm in length by 0.5 by 0.7 mm in width. And, its [[stigmoid]] apex measures 0.1 to 0.15 mm long by 0.3 to 0.5 mm wide.
Each [[carpel]] contains approximately 50 ovules.
====[[Fruit]]====
The fruit of ''Pachypodium brevicaule'' has two separate [[mericarps]] that form an angle of 5-45° at its base. Sometimes it is possible to see flowers on the same inflorescence that has fruit. Mericarps are the parts of a "[[schizocarp]]" fruit, that becomes dry at maturity and subsequently splits or breaks into several smaller pieces--''i.e. individual mericarp or seed. The mericarps are colored pale to dark brown with longitudinal lines outside and whitish inside when dried. The fruits are [[fusiform]] at 57 to 140 mm long (x) by 3 to 5 mm wide (y) by 2 to 4 mm high (z). They are obtuse, having a blunt or rounded tip, to acute, having a sharp point or tip, at the apex. The surface of the fruit is pubescent and hairy. The exterior wall is 1 mm thick.
=====[[Seed]]s=====
The seed of ''Pachypodium brevicaule'' Baker is pale brown. It is shaped in an [[elliptical]] manner. Its margin has a distinct broader that is [[revolute]], rolled backward from the tip or margins to the undersurface, towards the [[hilar]]. The hilar pertains the [[hilum]], which is a scar on a seed indicating the point of attachment to the [[funiculus]], the stalk connecting a seed with the placenta. The seed measures 3.5 to 3.9 mm in length by 1.5 to 1.8 mm in width. The [[testa]], the outer and normally hard and protective layer of the seed, is smooth. The coma of ''Pachypodium brevicaule'' Baker is straw-colored at 13 to 21 mm long. A coma is usually terminal tuft of hairs on a seed. In the case of ''Pachypodium'', the coma allows the seed to be airborne, as that is its means of distribution.
Whereas the [[embryo]] measures 3.2 to 3.5 mm in length, the [[cotyledons]] are 1.5 in length by 1.5 mm in width. The cotyledons are ovate in shape, meaning that they are broad and rounded at the base and tapering toward the apex. They are cordate, having a heart shape, at the base. The rootlet is 2 to 2.5 mm long by 1.2 mm wide. (Proportionately that is 1.3 to 1.6 times as long as cotyledons)
(3) Taxa tend to develop specialized xeromorphoric structures at some architectural level in [[arid]], geological and [[topology|topological]] landscapes, where a strategy of a "flexible" and "strict" architectural, organizational morphology at various levels of structure for ''Pachypodium'' becomes advantageous to succeeding in the isolated, specialized landscape. This strategy is seen in the manifest ''flexible'' variations of habit in species of ''Pachypodium'' while all the same they are "strictly" xeromorphic pachycaule trunks meant to conserve water for dry periods. At another level of structure, namely that of organs, we can see that [[dew]] and [[fog]] dripping spines are examples of a xeromorphic adaptive mechanized organ responding to microenvironments.
===Literature===
''Pachypodium brevicaule'' Baker
John Gilbert Baker published ''Pachypodium brevicaule'' in 1887 in Journ. Linn. Soc. Bot. 22: 503 (1887).
In 1934, J. M. H. A. Perrier de la Bâthie published an account of the taxon in Bulletin de la Société Botanique de France. 81: 303 (1934).
Pichon, in 1949, offers another account of ''Pachypodium brevicaule'' Baker in Mém. Inst. Sc. Madag. sér. B, 2: 122 (1949).
The latest account, before ''Rapanarivo et al'' is provided by Friedrich Markgraf within, Fl. Madag. fam. 169: 299 (1976).
The [[holotype|Species Type]] is: '''Madagascar, sin. loc., Baron 4412 ([[holotype]] The Herbarium of the Royal Botanical Garden at [[Kew]], near [[London]]; [[isotype]] The Herbarium of the Laboratoire de Phanérogamis at [[Paris]]). Fig. 3, p. 18; Map 2, p. 12; Plates 8-10, opposite p. 17.'''
===External sources===
==Taxonomy==
*Eggli, Urs. (1993) <u>Glossary of botanical terms with special reference to Succulent Plants</u>. with German Equivalents (British Cactus & Succulent Society: United Kingdom)
*Eggli, Urs. (1993) <u>Glossary of botanical terms with special reference to Succulent Plants</u>. with German Equivalents (British Cactus & Succulent Society: United Kingdom)
*Rapanarivo, S.H.J.V., Lavranos, J.J., Leeuwenberg, A.J.M., and Röösli, W. <u>Pachypodium (Apocynaceae): Taxonomy, habitats and cultivation</u> "Taxonomic revision of the genus Pachypodium," S.H.J.V. Rapanarivo and J.J. Lavranos; "The habitats of Pachypodium species" S.H.J.V. Rapanarivo; "Cultivation" W. Röösli. (A.A. Balkema: Rotterdam, Brookfield, 1999) [Rapanarivo et al.]
*Rapanarivo, S.H.J.V., Lavranos, J.J., Leeuwenberg, A.J.M., and Röösli, W. <u>Pachypodium (Apocynaceae): Taxonomy, habitats and cultivation</u> "Taxonomic revision of the genus Pachypodium," S.H.J.V. Rapanarivo and J.J. Lavranos; "The habitats of Pachypodium species" S.H.J.V. Rapanarivo; "Cultivation" W. Röösli. (A.A. Balkema: Rotterdam, Brookfield, 1999) [Rapanarivo et al.]
*Rowley, Gordon, D. Cactus Handbook 5: Pachypodium and Adenium (British Cactus and Succulent Society, (1983) 1999)
*Wikitionary: Terms
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{{pachypodium}}
{{Pachypodium}}
[[Category:Apocynaceae]]
[[Category:Apocynaceae]]
[[Category:Flora of Madagascar]]
[[Category:Flora of Madagascar]]
