Desmodium platycarpum Benth., Fl. Bras.

Lima, Laura Cristina Pires, Queiroz, Luciano Paganucci De, Tozzi, Ana Maria Goulart De Azevedo & Lewis, Gwilym Peter, 2014, A Taxonomic Revision of Desmodium (Leguminosae, Papilionoideae) in Brazil, Phytotaxa 169 (1), pp. 1-119 : 67-69

21. Desmodium platycarpum Benth., Fl. Bras. 15(1): 100. 1859. Meibomia platycarpa (Benth.) Kuntze, Revis. Gen. Pl. 1: 198. 1891. Lectotype (designated here):— BRAZIL. Mato Grosso: serra do rio Preto, September 1839, G. Gardner 2820 (K000328102!). Remaining syntypes: Brazil. Goiás: entre Serra de São Felix e de São Pedro, s.d., J.B.E. Pohl 435 (BR!, K!, M!, OXF!, W!), close to Missionem Duro, October 1839, G. Gardner 3114 (BM!, K!, OXF!, P!), close to Arrayas, March 1840, G. Gardner 3678 (BM!, K!, OXF!, W!), Sertão de Amaro Leite, October 1844, H.A. Weddell 2754 (K!); Minas Gerais: Estiva, A.F.C.P. Saint-Hilaire 925 (P!); Tocantins: rio Tocantins, July 1844, H.A. Weddell 2400 (K!). Fig. 23 .

Erect, branched subshrub, 0.5–1.5 m tall, with a xylopodium; stems not virgate, slender, cylindrical, striate, glabrescent or sparsely pubescent and puberulous-uncinate, not glaucous; internodes 4–18 cm long. Stipules ca. 4.5 × 0.5 mm, narrowly triangular, not auriculate, not amplexicaul, inserted perpendicularly at the base of the leaf petiole, free from each other, apex acute, margin straight, puberulous-uncinate and tomentose, veins inconspicuous, caducous. Leaves unifoliolate; petiole 1–8 mm long, cylindrical, sulcate, sparsely or densely sericeous–uncinate; stipels 1–3 mm long, subulate, margin straight, sparsely sericeous–uncinate, persistent; leaflet concolorous, chartaceous, venation brochidodromous, primary and secondary veins prominent, tertiary and quaternary veins flush on the abaxial surface, indumentum puberulous or glabrescent on the primary, secondary and tertiary veins on the abaxial surface, adaxial surface puberulous-uncinate, uncinate hairs covering both surfaces, leaflet 4.2–9.5 × 0.5–1.4 cm, elliptic, linear or oblanceolate, base oblique, obtuse or cuneate, apex subacute, obtuse or retuse, apiculate. Inflorescence a terminal paniculate; the main axis longer than the adjacent leaves, 13.5–35 cm long, sparsely or densely puberulous-uncinate, 2 flowers per node; primary bract 3–4 mm long, lanceolate, margin straight, hirsute and uncinate on the outer surface, caducous, veins conspicuous on the outer surface; secondary bract ca. 1 mm long, linear, margin straight, puberulous-uncinate on the outer surface, caducous, veins inconspicuous on the outer surface; pedicel 3–6 mm long, sparsely or densely puberulous-uncinate. Flowers 12–14 mm long; calyx bilabiate, tube campanulate, 1.5–2 mm long, tomentose and puberulous-uncinate on the outer surface; upper lip bifid, slightly fused, the 2 teeth joined for a ca. ¾ of their length, acute, ca. 0.1 mm long; lower lip trifid, lateral tooth triangular, 2–2.5 mm long, central tooth triangular, 2.5–3.5 mm long; corolla lilac, standard 11–12 × 7–10 mm, obovate, apex obtuse, maculate at the base, claw ca. 1 mm long; wing petals 11–12 × 3–4 mm, oblong, apex obtuse, without callosities, claw 1–2 mm long; keel petals 12–13.5 × 3–3.5 mm, narrowly obovate, apex subacute, with callosities, claw ca. 3 mm long; androecium monadelphous, 12–13 mm long, vexillary stamen partially fused with the other from the base 6.5–7 mm long; ovary 3–5 mm long, glabrous or glabrescent, stipe 2.5–3 mm long, glabrous. Loment 1.2–2.8 cm long, stipe 2–4 mm long, sericeous, isthmus marginal, upper suture straight or slightly invaginated and lower suture sinuate; articles uniform 1–3, 12–28 × 6–9 mm, obovatedepressed, not tortuous, indehiscent, membranaceous, veins inconspicuous, densely sericeous and uncinate. Seed 3–4.5 × 2.5–3.5 mm, orbicular, hilum subcentral.

Selected specimens examined:— BRAZIL. Distrito Federal: Brasília: fazenda Água Limpa, 10 September 1980, fl., fr., L . Fiedler 39 ( MBM). Goiás: Nova Glória : km 3 da rodovia Jardim Paulista Ubaitaba, 10 September 1996, B . A . S. Pereira & D. Alvarenga 3167 ( RB). Mato Grosso: Alto Araguaia: 22 Km do Alto Araguaia em direção a Rondonópolis, 22 September 1988, fl., R . Kral & M . G . L. Wanderley 75017 ( HUEFS, MBM). Mato Grosso do Sul: Rio Verde : BR-163, km 67,5, ca. de 9,5 km S da cidade de Rio Verde , 6 October 2008, fl., fr., L . C . P. Lima et al. 439 ( HUEFS). Minas Gerais: Buenópolis: Serra do Cabral , 7 Km da cidade, 12 October 1988, fl., R . M . Harley et al. 24883 ( HUEFS, SPF). São Paulo: São José do Rio Preto: Margem da rodovia BR-153, ca. de 2 Km Sul da

DESMODIUM (LEGUMINOSAE, PAPILIONOIDEAE ) IN BRAZIL

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LIMA ET AL.

represa, 12 October 1977, fl., J . R . Coleman & E . M . Menezes 70 ( SP). Tocantins: Arraias: Arraias , 5-10 Km oeste da rodovia Paranã, 10 November 1991, fl., fr., G . Hatschbach et al. 56014 ( HUEFS, MBM) .

Distribution and Ecology:— given by Lima et al. (2010) as being restricted to Brazil, but also known to occur in Bolivia and Paraguay. In Brazil D. platycarpum occurs in areas of the Cerrado biome in the Distrito Federal, and in the States of Bahia, Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo, and Tocantins.

Conservation Assessment:— Least Concern (LC), not endangered ( IUCN 2001).

Phenology:— flowering and fruiting from July to October.

Etymology:— from the Greek platy (= broad) + carpum (= fruit), a reference to the relatively broad fruit of the species.

Common Name:— unknown.

Taxonomic notes:— unifoliolate leaves, pseudoracemose inflorescences, flowers 12–14 mm long, fruit with 1–3 obovate-depressed, flattened, and densely villous articles are diagnostic characters of D. platycarpum . When sterile, the species can be confused with other unifoliolate species, such as D. pachyrhizum with ovate leaflets or D. polygaloides with linear leaflets. However, the prominent primary veins (only) on the abaxial surface of the leaflets of D. platycarpum (vs. prominent primary, secondary, tertiary, and quaternary veins on the abaxial surface of the leaflets of D. pachyrhizum , D. polygaloides , and D. sclerophyllum ) and the other aforementioned diagnostic characteristics of D. platycarpum help in the distinction of these taxa. Habitat can also help in the differentiation of D. platycarpum , as it generally occurs in dry pastures ( D. polygaloides prefers humid vegetation).

The obovate-depressed fruit articles of D. platycarpum are similar to those of D. riedelii , but the former can be differentiated by unifoliolate leaves (vs. trifoliolate), elliptic, linear, oblanceolate, or ovate leaflets 5.5–10.7 cm long (vs. lanceolate or oblong 2.9–4.9 cm long), and villous articles (vs. puberulous-uncinate).

Among the syntypes of Desmodium platycarpum examined, the collection “ Gardner 2820 ” (K000328102) is designated as the lectotype because it is the only specimen with leaves, flowers, and fruit in agreement with the protologue of the species published by Bentham (1859).

Figures

FIGURE 23. Desmodium platycarpum. A. Habit. B. Stipules inner surface. C. Detail of adaxial surface of leaflet. D. Calyx inner surface (opened). E. Parts of the corolla from the bottom to top: keel petals, wing petals, and standard. F. Androecium monadelphous (opened). G. Gynoecium. H. Fruit. I. Seed. (A–G: Lima 439; H–I: Pereira 3167).