Adesmia uruguaya Arechav., Anales Mus. Nac.

Monteiro, Thiago Cobra E, Iganci, João Ricardo Vieira, Miotto, Silvia Teresinha Sfoggia, Simpson, Beryl B., Vatanparast, Mohammad, Lewis, Gwilym P., Klitgård, Bente B., Pezzini, Flávia Fonseca, Vargas, Oscar M. & Fortuna-Perez, Ana Paula, 2024, Towards a Monophyletic Infrageneric Circumscription of Adesmia DC. (Dalbergieae, Leguminosae): a Taxonomic Revision in Adesmia series Adesmia, Phytotaxa 639 (1), pp. 1-69 : 61-63

21. Adesmia uruguaya Arechav., Anales Mus. Nac. Montevideo 3(20): 350 (1901).

Type:— URUGUAY. Tacuarembó: campos de Tacuarembó, January 1900, {fr.}, Arechavaleta , J. s/n (holotype: MVM barcode MVM005356 ; isotype: SI barcode 004105 [fragment, photo!]) .

= Adesmia punctata var. hilariana Benth., Fl. Bras. (Martius) 15(1A): 54 (1859).

Type :— BRAZIL. s.d., {fl./fr.}, St. Hilaire 2165 (lectotype designated here: P barcode P00758421 [photo!]); Sellow s/n (syntype: B, presumed destroyed) .

= Adesmia viciifolia Herter, Candollea 10:88 (1943).

Type :— URUGUAY. Minas: Arequita, 10 October 1907, {fl./fr.}, Osten , C. 5148 (holotype: G barcode G00364597 [photo!], isotype: SI barcode 004047 [photo!]) .

Prostrate to ascendant stoloniferous subshrubs with adventitious roots from stem branch nodes. Stem pubescent to glabrescent, white tector hairs intermixed with adpressed ochraceous glandular setules on all plant parts. Stipules 2–5× 0.5–1.5 mm, linear to narrowlY triangular, glabrescent. Leaves with 7–8 pairs of leaflets, the leaves closer to the inflorescences with 1–3 pairs of leaflets; petiole 0.5–2.2 cm long, rachis 0.7–3 cm long, pubescent; leaflets 3–9× 1–2.5 mm, obovate to narrowly elliptic, apex acute to rounded, base acute, margin entire, pubescent to glabrescent on both surfaces. Raceme terminal, usually axillary flowers at the inflorescence base, 4–27 cm long, pubescent; bracts 3–5 mm long, lanceolate, pubescent to glabrescent; pedicel 1–16 mm long, pubescent. Flowers 9.5–10.5 mm long; calyx 6–7 mm long, externally pubescent to muricate, stiff setules on the calyx tube, internally hirsute on the lobes with white tector hairs; lobes 3–4 mm long, narrowlY triangular to triangular; standard petal 10–14× 7–10 mm, wide-oboVate, apex emarginate, externallY pubescent, claw 4.5–6× 1–2 mm, internallY pubescent basallY; wing petals 9–11× 3–4 mm, oboVate, claw 4.5–5.5 mm long; keel petals 8–9× 3–4 mm, falcate, claw 3.5–4.5 mm long; stamens 8.5–9.5 mm long, anthers orbicular; gynoecium 10–12 mm long; ovary 4–5 mm long, pubescent, 4–6-ovulate. Hemicraspedium 9–12 mm long, straight, light to dark brownish, pubescent to muricate, abundant adpressed stiff thickened setules on the articles, fruit with 3–4 articles, these 2.5–3× 2–3 mm, orbicular. Seeds black, 1.5–2× 1.5–2 mm, orbicular, without an aril. ( Figure 34 ).

Distribution and Habitat— Adesmia uruguaya previously was considered to be endemic to the Uruguayan Pampas. During this revision, however, three collections from central Rio Grande do Sul state were located ( Fig. 33 ), extending the known distribution of this species to Brazil. The species is reported to inhabit open and shrubby grasslands.

Phenology— Flowering in October and fruiting in November (March).

Conservation status— Endangered (EN) B2ab(iii). The species has an EOO estimated at 37.357, 908 km ² and an AOO of only 32 km ², and known populations are severely fragmented. In addition, during the past few decades, the Pampas has faced changes in land use from cattle production on natural grasslands (which partially conserves natural habitats) to crop production, including soybeans and forestry ( Oliveira et al. 2017), putting increased pressure on the natural environment and threatening the future survival of Adesmia uruguaya .

Etymology— The epithet is a reference to Uruguay, the country where the species was first found, and until recently was believed to be endemic.

Notes— Adesmia uruguaya is easily distinguished from other species in the series Adesmia by the thickened stiff setules that cover the calyces and fruit articles ( Fig. 34 ), and by its leaves with fewer leaflets (3–5) at the base of the inflorescence. The species resembles A. incana in vegetative morphology, but also is distinguished by the adpressed glandular trichomes (vs. patent glandular trichomes in A. incana ).

Adesmia punctata var. hilariana has long been a confusing taxon. The variety was described by Bentham (1859) as having a short hirsute glandular indumentum, long pedicellate flowers, and short calyces with linear lobes. The specimens collected by St. Hilaire and Sellow were designated as type material ( Bentham 1859) and therefore are considered syntypes. Miotto and Leitão Filho (1993) mentioned that Sellow’s material was probably destroyed in the Berlin Herbarium (B) during World War II, and that St. Hilaire’s collection probably was to be found in P or, most likely, in K (because the variety was described by Bentham). Davyt and Izaguirre (1996) made no mention of the location of a type and Ulibarri and Burkart (2000) cited the type at K, even though they did not examine the specimen. In this study, we located the St. Hilaire collection in the Virtual Herbarium of St. Hilaire ( Pignal et al. 2013), which is deposited in the Paris herbarium (P) and carries the barcode P00758421. While analysing the image of the St. Hilaire syntype, we noted that the variety has fruit articles with thickened setules and calyces with triangular lobes, characters also found in A. uruguaya . Therefore, we have synonymized A. punctata var. hilariana under A. uruguaya , following article 11.2° of the Shenzhen Code (Turland. et al. 2018). The St. Hilaire material at P (P00758421) is also designated as a lectotype because Sellow’s syntype collection is presumed to no longer exist.

Adesmia viciifolia was described by Herter (1943). Osten 5148 was selected as the type ( Herter 1943), and it has leaves with fewer leaflets (3–5) at the base of the inflorescence, and fruit articles with thickened setules, the two main characters that diagnose A. uruguaya . Additionally, there are other overlapping characters, including indumentum type, calyx shape, and pedicel size, which led us to consider A. viciifolia as a synonym of A. uruguaya , in agreement with Davyt and Izaguirre (1996).

Additional Specimens Examined — BRAZIL. RIO GRANDE DO SUL: Santa Maria , 30 October 1936, Eisinger, S . s/n ( SMDB 204 ). 20 November 1988, Machado L. A. Z . 58 ( SMDB 3776 ). São Francisco de Assis, São Francisco de Assis / Santiago , 07 March 1990, Machado & Barreto 606 B ( SMDB 3767 ) . URUGUAY. Lavalleja: Arequita , 10 October 1997, Del Puerto 9446 ( MVFA) . Maldonado: Cerro Betete , 06 October 1963, Marchesi, E. H . 479 ( MVFA); ruta 60, km 18.5, 10 January 1991, Bayce, D. et al. s/n ( MVFA 22056 ) .

Figures

FIGURE 33. Geographical distribution of Adesmia subtropicalis Cobra, and A. uruguaya Arechav.

FIGURE 34. Adesmia uruguaya Arechav. A. Leaf with oblong to elliptic opposite leaflets, their adaxial and abaxial surfaces pubescent. B–D. Leaflet with the abaxial surface with both glandular and tector trichomes. E. Flower; calyx lobes longer than the tube. F. External indumentum of the calyx with long ochraceous glandular trichomes, the base stiff.G. Hemicraspedium with spherical articles.H. Persistent calyx on the fruit with thickened stiff glandular trichomes. I. Article of the lomentum with thickned glandular trichomes covering the whole surface of the article. J. Thickned stiff glandular trichomes on the fruit article. (Voucher: A–D, G–J: Machado, L. A. Z. 58; E–F: Machado & Barreto 606B).