Desmanthus Willd., Sp. Pl. 4: 1044. 1806.
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https://dx.doi.org/10.3897/phytokeys.240.101716 |
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https://treatment.plazi.org/id/415D685A-89DA-9CB1-4988-362514F68CA4 |
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scientific name |
Desmanthus Willd., Sp. Pl. 4: 1044. 1806. |
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Desmanthus Willd., Sp. Pl. 4: 1044. 1806. View in CoL
Figs 144 View Figure 144 , 145 View Figure 145 , 146 View Figure 146 , 153 View Figure 153
Acuan Medik., Theodora: 63. 1786, nom. rej. vs. Desmanthus Willd. Type: Acuan virgatum (L.) Medikus [(≡ Desmanthus virgatus (L.) Willd.)]
Darlingtonia DC., Ann. Sci. Nat. (Paris) 4: 97. 1825. Type: Darlingtonia brachyloba (Willd.) DC. [≡ Acacia brachyloba Willd. (≡ Desmanthus illinoensis (Michx.) MacMill. ex B.L. Rob. & Fernald)]
Type.
Desmanthus virgatus (L.) Willd. [≡ Mimosa virgata L.]
Description.
Unarmed, mostly woody shrubs or small trees to 4 m, or functionally herbaceous perennials much-branched from a woody base (Fig. 144F, G View Figure 144 ), arising from a stout cylindrical or napiform tap root and dying back annually to the base in temperate regions, brachyblasts present in woody species. Stipules usually persistent, setiform with a dilated, auriculate base. Leaves bipinnate, extrafloral nectaries between proximal pair of pinnae and sometimes other pinnae pairs; pinnae 1-9 (17) pairs, opposite; leaflets 5-45 (55) pairs per pinna, opposite, variable in size and shape (linear, oblong, elliptic). Inflorescences capitate, peduncle sometimes with a distal involucel of united bracts, 1 (2) in leaf axils, composed of variable proportions of sterile, functionally staminate, and hermaphrodite flowers, rarely all of one type (Fig. 145F View Figure 145 ); bracteoles subtending each flower deltate, peltate. Flowers with sepals valvate in bud, petals valvate; sterile flowers borne proximally, with elongated showy white, or rarely pink, filamentous staminodia (Fig. 145F View Figure 145 ), ovary vestigial but like the fertile flowers in other respects; fertile flowers with the calyx cupulate, 5-lobed; petals 5, free, white or pale green; stamens 10 (5 in one species), filaments white or pink, anthers glabrous, lacking an apical gland; pollen in symmetric tricolporate monads, the exine striate, fossulate or foveolate; ovary sessile, glabrous or rarely pubescent, stigma funnelform. Fruits linear, flattened, valves chartaceous or coriaceous, seeds oblique or longitudinal, inertly dehiscent along both sutures (Fig. 146E View Figure 146 ) (indehiscent in one species). Seeds ovate to rhomboidal, pleurogram U-shaped.
Chromosome number.
2 n = 28 ( Turner and Beaman 1953).
Included species and geographic distribution.
23 species. Three endemic species in the USA, with six extending to Mexico, six endemic species in Mexico, with three species extending to South and Central America, one endemic to Argentina, two bicentric in the USA and Argentina, one in the Antilles and north-western South America, one widespread USA to Argentina (Fig. 153 View Figure 153 ). One species, Desmanthus pernambucanus (L.) Thell. (often mis-identified as D. virgatus ), is weedy and widely introduced throughout the tropics.
Ecology.
Seasonally dry tropical forest and semi-arid thorn scrub (ca. 10 species); warm temperate scrubland and oak woodland (seven species), three species extending to cool temperate grasslands and woodlands, two species in wet tropics (but absent from the Amazon basin), very often in disturbed open habitats, abandoned pastures and coastal thickets. Seed dispersal passive. Usually deciduous. Nodulating, symbiosome present. Bee-pollinated ( Xylocopa and generalist bee species).
Etymology.
From Greek, desme (= bundle) and anthos (= flower), in reference to dense capitate inflorescences.
Human uses.
Used as ornamentals, livestock fodder and in erosion control; Desmanthus illinoensis (Michx.) MacMill. ex B.L. Rob. & Fernald is used for food (leaves, cooked seeds), medicine and is a potential pulse crop ( Luckow 1993).
Notes.
The delimitation of Desmanthus was altered by Hughes et al. (2022b) to account for the non-monophyly of the genus and exclude the morphologically and phylogenetically distinct species Desmanthus balsensis , which was placed in the new genus Mezcala .
Taxonomic references.
Luckow (1993), including illustrations; Luckow et al. (2003, 2005).
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.