Meibomia glabrescens (Malme) Schindl., Repert., 2014

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 : 43-45

11. Desmodium glabrescens Malme, Ark. Bot. 18(7): 18. 1922. Meibomia glabrescens (Malme) Schindl., Repert. Spec. Nov. Regni Veg. 20: 148. 1924. Type :— BRAZIL. Mato Grosso: Chapada dos Guimarães, "Santa Ana da Chapada, G.O.A. Malme II 3413 " (holotype S!, isotype R!). Fig. 13 .

Erect, branched shrub, 0.5–2 m tall, with a xylopodium; stems not virgate, not slender, cylindrical, sulcate, glabrous or sparsely puberulous-uncinate, not glaucous; internodes (1.9–) 2.8–5 cm long. Stipules 2–3 × 1–1.5 mm, triangular, not auriculate, semi-amplexicaul, inserted perpendicularly at the base of the leaf petiole, free from each other, apex caudate, margin straight, sparsely puberulous, veins conspicuous, caducous. Leaves trifoliolate; petiole (15–) 19–37 mm long, cylindrical, sulcate, hirsute, uncinate or puberulous-uncinate; rachis (11–) 15–28 mm long; stipels 3–6 mm long, subulate, margin straight, glabrescent on the outer surface, persistent; leaflets discolorous, chartaceous or membranaceous, venation brochidodromous, primary and secondary veins prominent, tertiary veins flush with the abaxial surface, indumentum sparsely, rarely densely tomentose on the primary and secondary veins, glabrous rarely tomentose, on the tertiary veins on the abaxial surface, adaxial surface glabrous or puberulous, uncinate hairs covering both surfaces, terminal leaflet (6.2) 7.5–10.6 × 3.4–5.5 cm, ovate-lanceolate or elliptic, base oblique or obtuse, apex subacute or retuse, lateral leaflets 4.2–5.1 × 2.5–3.4 cm, oblong or the same shape as the terminal leaflet. Inflorescence a terminal or axillary pseudoraceme; the main axis longer than the adjacent leaves, (24–)34–37.2(–45) cm long, densely hispid, with uncinate hairs, 2 flowers per node; primary bract 3–6 mm long, lanceolate, margin straight, puberulous-uncinate or glabrous on the outer surface, caducous, veins conspicuous on the outer surface; secondary bract 2–3 mm long, linear, margin straight, sparsely hispid or uncinate on the outer surface, caducous, veins inconspicuous on the outer surface; pedicel (6–) 8–10 mm long, densely hispid. Flowers 8–9 mm long; calyx bilabiate, tube campanulate, 1.5–2 mm long, tomentose on the outer surface; upper lip entire, apex retuse; lower lip trifid, lateral tooth ovate, 1.5–2 mm long, central tooth lanceolate, 2–2.5 mm long; corolla lilac, standard 8–9 × 5–6 mm, obovate, apex obcordate or obtuse, maculate at the base, claw 0.5 mm long; wing petals 7–9 × 1.5–2 mm, oblong, apex obtuse, without callosities, claw ca. 1 mm long; keel petals 7–9 × 2–3 mm, narrowly obovate, apex subacute or obtuse, with callosities, claw 3–4 mm long; androecium monadelphous, 8–9 mm long, vexillary stamen partially fused with the other from the base 2–3 mm long; ovary 3–5 mm long, glabrous stipe 2–3 mm long, glabrous. Loment 2.1–2.5 cm long, stipe 2–3 mm long, glabrous or puberulous-uncinate, isthmus central, both margins sinuate; articles uniform 5–7, 2–4 × 2.5–3 mm, rhombic, tortuous, indehiscent, membranaceous, veins insconspicuous, puberulous-uncinate. Seed 2.5–3 × 1.5 mm, elliptic, hilum subcentral.

Selected specimens examined:— BRAZIL. Distrito Federal: Brasília: Região da Palma , 9 June 1981, fl., P . Gutierres 24 ( HUEFS). Goiás: Cana Brava : s. loc., 14 June 1990, fl., fr., R . R . Brooks et al. 496 ( K). Mato Grosso: Chapada dos Guimarães: trilha histórica Top de Fita , conhecida também como trilha da Bocaína, tangente ao Parque Nacional da Chapada dos Guimarães, 21 April 2009, st, L . C . P. Lima & N . Salzstein 624 ( HUEFS); Trilha da Mata Fria, Coxipozinho, próximo à Barra do Congonhas , Parque Nacional da Chapada dos Guimarães , 21 April

DESMODIUM (LEGUMINOSAE, PAPILIONOIDEAE ) IN BRAZIL

Phytotaxa 169 (1) © 2014 Magnolia Press • 43 44 • Phytotaxa 169 (1) © 2014 Magnolia Press

LIMA ET AL.

2009, fl., L. C. P . Lima & N . Salzstein 620 ( HUEFS); Grotão da Anta , APM Manso, 17 May 2000, fl., N . Somavilla 23 ( UFMT). Minas Gerais: Uberlândia: Reservatório de Miranda, ca. 20 km do município de Uberlândia, 29 April 2003, fl., R . Romero et al. 6802 ( ESA) .

Distribution and Ecology:— D. glabrescens occurs only in Brazil, in the Distrito Federal and in the States of Goiás, Mato Grosso, and Minas Gerais. The species grows in the Cerrado biome in areas of forest, in open microhabitats such as clearings or trails, on stony soils.

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

Phenology:— flowering and fruiting from April to June.

Etymology:— from the Latin glabrescens (= glabrescent), a reference to the stems which are almost glabrous.

Common Name:— unknown.

Taxonomic notes:— large flowers (8–9 mm long), a glabrous ovary, and tortuous fruit articles are distinguishing characteristics of this species. The elliptic leaflet shape is similar to that of D. cajanifolium , D. leiocarpum , and D. subsecundum , but in D. glabrescens the leaflets are glabrous (or rarely tomentose) on the tertiary veins of the abaxial surface. The glabrous ovary and tortuous articles of D. glabrescens are similar to those of D. membranifolium and D. tortuosum , but the latter two species possess auriculate stipules (vs. non–auriculate in D. glabrescens ). Furthermore, D. membranifolium has unifoliolate leaves (vs. trifoliate in D. glabrescens ) and D. tortuosum has flowers only 4–5 mm long (vs. 8–9 mm).

The collection Pohl 1689 (W!) was cited by Schindler (1926) as Meibomia bridgesii Schindl. , which is correctly identified as D. glabrescens . Desmodium glabrescens and D. bridgesii (Schindl.) Burkart are similar in the form of the terminal leaflets (ovate-elliptic or elliptic), glabrous or puberulous adaxial leaflet surface, paniculate inflorescence, and large flowers (8–9 mm long). However, the two species can be distinguished based on fruit morphology, with articles rhombic and tortuous in D. glabrescens (vs. oblong and not tortuous in D. bridgesii ). Moreover, D. glabrescens has been recorded only in Brazil, whereas D. bridgesii occurs in Argentina, Bolivia, and Paraguay.

Figures

FIGURE 13. Desmodium glabrescens. A. Fruiting branch. B. Stipules inner surface. C. Calyx inner surface (opened). D. Parts of the corolla from the bottom to top: keel petals, wing petals, and standard. E. Androecium monadelphous (opened) and Gynoecium. F. Fruit. G. Seed. (A, F–G: Malme 3413; B–E: Lima 624).