Astragalus darwinianus (Leguminosae, Galegeae), a New Species from Argentina Edith Gomez-Sosa Instituto de Botainica Darwinion, CC 22, B 1642HYD San Isidro, Argentina.
[email protected] Astragalus darwinianus G6mez-Sosa.a new endemic species (Leguminoseae, Galegeae)from the south of Argentina, is described, illustrated,and compared with the morphologically similar A.patagonicus (Philippi) Spegazzini based on vegelativecharacteristics and with A. mendocinus (;mez-Sosabased on fruit morphology. The new entity hasdecumbent stems, racemes thai are (2)3-to 4-flowered, and legumes that are unilocular. incurvedI.and incanous pubescent.RESUMEN. Astragalus darwinianus G6mez-Susa, unanueva especie endemica del sur de Argentina, sedescribe, ilustra y se compara con A. patagonicus(Philippi) Spegazzini con las que comparte caracter-isticas vegetativas y con A. mendocinus Gomez-Sosasimilares por la morfologfa del frulo. El nuevoejemplar tiene tallos decumbentes, racimos con(2)3-4 flores, legumbre unilocular, incurva e incanoi)ublescenle. Key words: Argentina, Astragalus, (alegeae. Le-guminosae, Patagonia. The genus Astragalus L. (Leguminosae, Galegeae)in South America is represented by approximately 110species found in Ecuador, Peru, Bolivia, Chile,Uruguay, and Argentina, as presently revised (G6-mez-Sosa, 1979, 1999). In Argentina there are about70 species from the north, in the province of Jujuy, tothe south in the province of Tierra del Fuego. Itinhabits the western areas from the Andean mountainsat about 4700 m altitude, extending to the southeastalong the Atlantic coast in Patagonia (Comez-Sosa,2005). The contribution presented here is relevant tothe Patagonian region with 29 species (Gdmez-Sosa,1984).Astragalus darwinianus Godmez-Sosa. sp. nov. TYPE: Argentina. Santa Cruz. Dpto. Lago Argentino: 30 km E of Calafate. near Santa Cruz river, 190 m, 50�15'47"S. 071�53'10"W, 21 Dec. 2002, 1. DBenjamini 911 (holotype, SI; isotypes, CTES, MO). Figure 1. Herba prostrata. caulius dtcumrbentibius; stilulae am-plexicaules, bilentatae. glabrae. ciliataec folia 4-6 cm longa.pcliolo 2-3 cm incluso: foliola 9 ad 11, linearia veI elliplica.8-10 X 1.5-2.5 m111I. supra glabra, subliis alla strigoso-[ipubescentia, in rachidi 0.8 cim distantia. conduplicata, apiceobtuso: raccni laxi (2)3-ad 4-flori; pcdiiinulit quam toliaaeqiuilongi; nfores (0.5-)0.7-1 cm pediccllali. erecti adasccndentes. calyx canmlanulaltus, 2-bractcolatus; vcxillum1.25 X 1 crm; legumen inmmaliurun. ca. 3 X 0.25 cm,fusiformc, lunate incurvum, uniloculare, iapyraceum, api-culatum. marginiblus fusifiormibus. incane )lpu scens. later-aliler c(iipressum el lineare in trainseciouc. Prostrate caulescent herb: stems 2-4 enm siipulesmembranous, connate and amplexicaulous into a short-ly bidentate sheath, glabrous, ciliate. Leaves 4-6 cm,including petiole 2-3 cm; leaflets 9 to 11. distant bynearly 0.8 cm on the rachis, in outline linear orelliptic, obtuse, 8-10 X 1.5-2.5 mm, glabrousabove, white strigose-pubescent below. Racemesloosely (2)3-to 4-flowered: peduncles 4-5.5(-6) erm,decumbent in age; bracts 2.5 nmm, subulate, glahrous.ciliolate; bracteoles 2, 1.2 mrm. Flowers blue-violet topale blue, pedicels (0.5-)0.7-1 cm, erect to ascend-ing; calyx 7.5 cm. canescent, tube campanulate4 mm, teeth subulate 3.5 rmm: banner 1.25 X1 cm, erect, obtuse; wings 1.25 X 0.25 em. withthe claws included, narrowly rectangular: keel1.15 em; ovary subslipitate. pubescent, style glabrous.stigma capitate; ovules ca. 28. Pod immature.canescent, ca. 3 X 0.25 cm. fusiform, papery.incurved throughout for ca. 1/6-1/3 of a circle, thestipe concealed in the lhypanlhial cup, unilocular. notinflexed, papery, carinate dorsally, laterally com-pressed and linear in cross section. Etymology. This species is dedicated to CharlesDarwin (1809-1882) who, at 22 years of age. wasinvited by Captain R. FitzRoy to travel on the Beaglearound the worl as thlie naturalist on the voyage.Darwin's longest stay on land was in the region aroundand south of the La Plata River, Brazil, Uruguay, andArgentina (this included Patagonia and Tierra delFuego), wxhere he explored for 20 months and six days,from 26 July 1832 to 2 April 1834. On 16 April 1834,along the coast of Argentine Patagonia, the BeagleNOVON 17: 179-181. PtnLlusHli) ON 20 JuNi: 2007.
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