Desmodium venosum Vogel, Linnaea
Creators: name: Lima, Laura Cristina Pires
name: Queiroz, Luciano Paganucci De
name: Tozzi, Ana Maria Goulart De Azevedo
name: Lewis, Gwilym Peter
Publisher: name: Zenodo
Year: 2014
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Magnoliopsida
Fabales
Fabaceae
Desmodium
Desmodium venosum

description: 33. Desmodium venosum Vogel, Linnaea 12: 103. 1838. Meibomia venosa (Vogel) Kuntze, Revis. Gen. Pl. 1: 198. 1891. Lectotype (designated here):— BRAZIL. Brasil meridional, F. Sellow s.n. (lectotype K000328116!, isolectotypes E!, K000328115!). Fig. 35.   
Erect, branched shrub or subshrub, 0.5–1.4 m tall, lacking stolons rooting at the nodes, xylopodium not seen; stems not virgate, slender or not, cylindrical, striate, uncinate, glabrescent or sparsely uncinate and hirsute, rarely, not glaucous; internodes 1.9–3.8 cm long. Stipules 4–6 × 1–1.5 mm, ovate-lanceolate, not auriculate, semiamplexicaul, inserted perpendicularly at the base of the leaf petiole, free from each other, apex caudate, margin ciliate, tomentose, veins conspicuous, caducous. Leaves trifoliolate, rarely unifoliolate on the same plant; petiole 3–6 mm long, cylindrical, sulcate, densely hirsute; rachis 8–9 mm long; stipels 3–4 mm long, subulate, margin straight, glabrescent on the outer surface, caducous; leaflets discolorous, chartaceous, venation eucamptodromous, primary, secondary, tertiary and quaternary veins prominent with the abaxial surface, indumentum densely hirsute or tomentose on the primary, secondary and tertiary veins on the abaxial surface, adaxial surface puberulous, uncinate hairs covering both surfaces, terminal leaflet 3.5–7.6 × 0.6–1.8 cm, elliptic, narrowly elliptic, oblong or ovate, base oblique or cuneate, apex subacute or obtuse, mucronate, lateral leaflets 2.9–3.4 × 0.7–0.8 cm, the same shape as the terminal leaflet. Inflorescence a terminal pseudoraceme or paniculate; the main axis longer than the adjacent leaves, 13.5–24.2 cm long, densely uncinate and hirsute, 2 flowers per node; primary bract 2.5–3 mm long, lanceolate, margin ciliate, puberulous-uncinate on the outer surface, caducous, veins inconspicuous on the outer surface; secondary bract 0.5–1 mm long, linear, margin ciliate, hirsute on the outer surface, caducous, veins inconspicuous on the outer surface; pedicel 3–6 mm long, sparsely or densely uncinate. Flowers 5–7 mm long; calyx bilabiate, tube campanulate, 1–1.5 mm long, puberulous-uncinate and tomentose on the outer surface; upper  
 DESMODIUM (LEGUMINOSAE, PAPILIONOIDEAE) IN BRAZIL   
 Phytotaxa 169 (1) © 2014 Magnolia Press • 97 98 • Phytotaxa 169 (1) © 2014 Magnolia Press   
 LIMA ET AL.   
lip bifid, oblong, the 2 teeth joined for ca. ¾ of their length, apex acute, ca. 0.2 mm long; lower lip trifid, lateral tooth lanceolate, 1–1.5 mm long, central tooth lanceolate, 1.5–2.2 mm long; corolla lilac, standard 5–7 × 3–3.5 mm, obovate, apex retuse or obtuse, maculate at the base, claw 2–2.5 mm long; wing petals 4–6.5 × 1.5–2 mm, oblong or narrowly obovate, apex obtuse, without callosities, claw 0.8–1 mm long; keel petals 5–7 × 1.5–2 mm, narrowly obovate, apex subacute, with callosities, claw 2–3 mm long; androecium monadelphous, 5–7 mm long, vexillary stamen partially fused with the other from the base 3–4 mm long; ovary 3–3.5 mm long, tomentose, stipe 0.5–1 mm long, glabrous. Loment 1.2–2.5 cm long, stipe 1–2 mm long, glabrous or puberulous, isthmus central or subcentral, both margins sinuate; articles uniform 3–6, 3–5 × 1.5–3 mm, ovate-elliptic or orbicular, not tortuous, indehiscent, subcoriaceous, veins conspicuous, sparsely puberulous-uncinate. Seed 1.5 × 1 mm, elliptic, hilum central.  
 Selected specimens examined:— BRAZIL. Mato Grosso do Sul: Nova Alvorada do Sul: BR 163, km 388, ca 6km S do Córrego de Santa Luzia, 11 April 2009, fl., fr., L. C. P . Lima & M. P. Andrade 572 (HUEFS). Paraná: Almirante Tamandaré: Parque Santa Maria, 10 January 1967, fl., fr., G . Hatschbach 15638 (K, MBM, U). Rio Grande do Sul: Itaara: Reserva do Ibicuí-Mirim, após o Passo da Rede, 5 March 2009, fl., fr., L. C. P . Lima et al. 556 (HUEFS). Santa Catarina: São Joaquim: rodovia São Joaquim-Bom Jesus, descida ao rio Pelotas, 11 March 2005, fr., G . Hatschbach et al. 79033 (MBM).   
 Distribution and Ecology:— South America in Argentina, Brazil and Uruguay (Izaguirre & Beyhaut 1998, Vanni 2001, Lima et al. 2010). In Brazil D. venosum occurs in the States of Mato Grosso do Sul, Paraná, Rio Grande do Sul, and Santa Catarina, in grasslands of the Cerrado and Pampa biomes.   
 Conservation Assessment:— Least Concern (LC), not endangered (IUCN 2001).   
 Phenology:— flowering and fruiting from January to March.   
 Etymology:— from the Latin venosus (= having many conspicuous veins), in reference to the prominent veins on the abaxial surface of the leaflets.   
 Common Name:— carrapicho; pega-pega.   
 Taxonomic notes:— erect habit, trifoliolate leaves (rarely unifoliolate at the base of inflorescences), leaflet shape (with conspicuous veins at the base on the abaxial surface of the leaflets), flower 5–7 mm long, ovary tomentose, fruit articles elliptic, narrowly elliptic or orbicular with conspicuous veins are all diagnostic of D. venosum. The species is similar to D. hassleri, D. leiocarpum, D. microcarpum and D. subsecundum (see notes under those species).   
 Malme (1931) cited the collection "Sellow 3306, Caçapava, RS", as the type of Desmodium venosum, and this could be considered the first typification of the species. However the Sellow specimen was not found in herbaria consulted during the course of our studies; in the Eand K herbaria, we analysed the collection "Sellow s.n., Brasil " of D. venosum, identified in the handwriting of Vogel and the specimen K000328116 is here chosen as the lectotype of D. venosum as its inflorescence and leaflets accord well with the protologue of Vogel (1838).
description: Published as part of 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, pp. 1-119 in Phytotaxa 169 (1) on pages 97-99, DOI: 10.11646/phytotaxa.169.1.1, http://zenodo.org/record/10089817