7. Adesmia grisea Hook.f., Bot. Antarct. Voy. I. (Fl. Antarct.) . 2: 257 (1846).

Type:— ARGENTINA. Hab. Patagonia, South latitude 40°, s/d, {fl.}, Tweedie, J . s.n. (holotype: K barcode K000328024!) .

≡ Patagonium griseum (Hook.f.) Speg., Anales Mus. Nac. Buenos Aires 7: 273 (1902).

≡ Adesmia incana var. grisea (Hook.f.) Burkart, Colecc. Ci. Inst. Nac. Tecnol. Agropecu. [Cabrera] 4(3a): 479–480 (1967b).

= Adesmia angulata Hook.f., Bot. Antarct. Voy. I. (Fl. Antarct.) . 2: 257 (1846). syn. nov.

Type:— ARGENTINA. Río Uruguay, s/d, {fl.}, Tweedie, J. 345 (lectotype, designate here: K barcode K000328029!, isolectotypes K barcode K000328025!; SI barcode 003991 [fragment, photo!]) .

Prostrate to ascendant subshrubs, adventitious roots from stem branch nodes absent. Stem pubescent to glabrous, adpressed white tector hairs on all plant parts. Stipules 1.5–4× 0.5–1 mm, linear to triangular, pubescent. Leaves with (4–)6–10 pairs of leaflets; petiole 0.4–2 cm long, rachis 1–5 cm long, pubescent; leaflets 2–11× 0.5–3 mm, linear to obovate, apex rounded to mucronate, base acute, margin entire, pubescent to glabrescent. Raceme axillary or terminal, 4–15 cm long, pubescent; bracts 1.5–3 mm long, deltate to lanceolate, pubescent; flowers subsessile to pedicellate, pedicel 1–9 mm long, pubescent. Flowers 10–13 mm long; calyx 6–9.5 mm long, externally and internally pubescent, lobes 2–6 mm long, linear to triangular; standard petal 12–13.5× 7–10 mm, orbicular to flabelliform, apex emarginate to obtuse, externallY pubescent, claw 5–7× 1–2 mm, glabrous; wing petals 8.5–12× 2–4 mm, oblong to narrowlY-oboVate, claw 3–6 mm long; keel petals 8–10× 3–4 mm, falcate, claw 3.5–6.5 mm long; stamens 7–12 mm long, anthers elliptical to oblong; gynoecium 7.5–12 mm long; ovary 3–5 mm long, pubescent, 2–6-ovulate. Lomentum 7–17 mm long, straight, brown to grayish, pubescent, sparce stiff black setules at the centre of each article, fruit with 2–6 articles, these 2.5–3× 2.5–3 mm, orbicular. Seeds brown, 2–2.5× 1.5–2 mm, reniform, without an aril. (Figures 13 and 14).

Distribution and Habitat— Adesmia grisea occurs in northeast Argentina, in the Provinces of Buenos Aires, Cordoba, Corrientes, La Pampa and Entre Ríos (Fig. 15), and rarely in Uruguay. The species inhabits open grasslands and dry open savannas.

Phenology— The species bears flowers and fruits from October to December.

Conservation status— Vulnerable (VU) B2a,b(iii). Adesmia grisea occurs mainly in the Argentinian Pampas (with three records from Uruguay). The populations are severely fragmented, as the species has an EOO of 366.109, 483 km ², but an AOO of only 36 km ² (nine known locations). In addition, the species populations occur near Buenos Aires, one of the largest cities in South America, and are exposed to habitat conversion, degradation and fragmentation.

Etymology— Joseph Dalton Hooker, the botanist that described the species, alluded to the gray indumentum that covers the plant and thus the species epithet grisea .

Notes— Burkart (1967b) established Adesmia incana var. grisea based on A. grisea, and synonymized A. angulata under A. incana . After a careful analysis of several specimens, including type material of Adesmia incana and A. grisea, we consider Adesmia grisea to be a well-delimited taxon worthy of the rank of species. The features that distinguish the species are the absence of glandular trichomes on the leaves and stem, and the lomentaceous fruit with few glandular trichomes at the centre of each article (Figs. 13 and 14) (vs. glandular trichomes present on the leaves and stem, fruit a hemicraspedium, and an abundance of glandular trichomes on the fruit articles in A. incana).

Adesmia grisea was described in 1844 based on the material of Tweedie s.n. from “Patagonia, south latitude 40º” as the type collection (K000328024). The species was described together with A. angulata, which Hooker described as “differt ramis ascentibus angulates, floribus majoribus, segmentisque calycinis elongatis” (Hooker 1844). The differences described by Hooker occur in different plants from the same populations, and sometimes even on the same individual plant. Because of morphological plasticity both in habit (ascendant or prostrate) and in calyx lobe length, we have synonymized A. angulata under A. grisea .

Phylogenetically (Fig. 1), the species is sister to a clade containing all other species of the previously recognised series Bicolores and Subnudae (Fig. 1). It has a lomentum and a lack of adventitious roots from branch nodes, characters present in some species of series Muricatae of Burkart (1967a).

In the protologue of Adesmia angulata, Hooker (1844) indicated a Tweedie collection as the type. In the Kew Herbarium (K) we found two specimens, labelled with a Herbarium Hookerianum stamp, which were originally identified as A. angulata . As Ulibarri and Burkart (2000) did not select either of these specimens as a lectotype, we propose here the Kew specimen K000328029, which has fruits and flowers, as the lectotype of Adesmia angulata .

Additional Specimens Examined — ARGENTINA. BUENOS AIRES: Campana Partido, Otamendi, 1–2 km hacia Campana, Baranca de río Paraná 24 December 1982, Hunziker, J. H. 10181 (TEX [photo!]) . Parana, bords du Parana, 1819, Bonpland, A. s/n (P P02936400 [photo!]) . “Barranca” du fleuve Parana, 1819, Bonpland, A. s/n (P P02936397 [photo!]) . Partido Gral., Alvadaro, Miramar, 31 March 1951, Pedersen, T. M. 1038 (P P02936399 [photo!]) . CORDOBA: San Alberto, Inmediaciones estación San Miguel, 15 December 1987, Espinar, L. A. 3067 (MBM 300057) . CORRIENTES: Santa Maria, Sierra Chica ( Falda 0), Bosque Alegre, em las inmediaciones del observatorio astronômico, 30 October 1949, Hunziker, A. T. 7904 (MBM 377208) . Sauce, Chacra El Timbó, 3 km N de Sauce, 22 October 1977, Ahumada, O. 1300 (MBM 58220) . ENTRE RÍOS: Concepción del Uruguay, aeródromo, 16 December 1957, Burkart, A. 20588 (CEN 00014369 [photo!]) . Ferderación, Estância Buena Esperanza, 21 October 1961, Pedersen, T. M. 6211 (L 135632 [photo!]) . Paraná, Cerro caminho a La Toma, 02 November 1962, Burkart, A. 23680 (MBM 70457) . LA PAMPA: General Acha, 01 December 1959, Bacigalupo, N. M. 20647 (P P02936395 [photo!]) . URUGUAY. COLONIA: Punta Piedras, 10 November 1946, Castellanos, A. 15985 (P P02936402 [photo!]) . LAVALLEJA: la Capelha de Minas, 1816-1821, Saint-Hilaire 2429 (P P02936396 [photo!]) .