Adesmia retrofracta Hook. & Arn., Bot. Misc.

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 : 51-52

15. Adesmia retrofracta Hook. & Arn., Bot. Misc. 3: 188 (1830).

Type:— ARGENTINA. Mendoza: La Puente del Sauce, and on the road to Papagayos, mountains of Mendoza, s.d., {fl./fr.}, Gillies , J. s.n. (lectotype designated by Ulibarri and Burkart [2000]: K barcode K000327982!, isolectotype: E barcode E00089172 [photo!]).

≡ Patagonium retrofractum (Hook. & Arn.) Kuntze, Revis. Gen. Pl. 1: 201 (1891).

= Patagonium polygaloides Chodat & Wilczek, Bull. Herb. Boissier ser. 2, 2: 482, Fig. 5 , (1902).

Type:— ARGENTINA. Mendoza: San Rafael, Cerro Bola, 1897, {fl./fr.}, Wilczek, E. 89 (holotype LAU; isotypes: US barcode US 00001940 [photo!]; P barcode P02936901 [photo!]; type negative F 27915 [photo!]).

≡ Adesmia polygaloides (Chodat & Wilczek) Burkart, Darwiniana 3(2): 331 (1939).

= Patagonium retrofractum var. rectirostris Chodat & Wilczek, Bull. Herb. Boissier ser. 2, 2: 481 (1902).

Type:— ARGENTINA. Mendoza: San Rafael, Cerro Bola, Wilczek, E. 120 (holotype: LAU).

≡ Adesmia retrofracta var. rectirostris (Chodat & Wilczek) Burkart, Darwiniana 3(2): 334 (1939).

= Patagonium rafaelense Chodat & Wilczek, Bull. Herb. Boissier ser. 2, 2: 485 (1902).

Type:— ARGENTINA. Mendoza: San Rafael, Cerro Bola, Wilczek, E. 121 (holotype LAU).

≡ Adesmia rafaelensis (Chodat & Wilczek) Hicken, Physis (Buenos Aires) 2(9): 17 (1916).

Ascendant to erect shrubs or subshrubs, adventitious roots from stem branch nodes absent. Stem pilose to glabrescent, with sparse adpressed white tector hairs intermixed with abundant ochraceous glandular setules on all plant parts. Stipules 2–4× 1–2 mm, narrowlY triangular to deltate, pubescent to glabrous. Leaves with 6–8(–12) pairs of leaflets; petiole 0.5–3 cm long, rachis 1–5.5 cm long, pubescent to pilose; leaflet 3–9× 1–5 mm, elliptic to orbicular, apex truncate to acuminate, base rounded, margin entire, pubescent to glabrescent on both surfaces. Raceme terminal or axillary, 8–26 cm long, pubescent to glabrescent; bracts 1.5–2 mm long, lanceolate to deltate, pubescent to glabrescent; pedicel straight or reflexed after anthesis, 3–10 mm long, pilose to pubescent. Flowers 9–12 mm long; calyx 3.5–4.5 mm long, externally pilose to pubescent, internally hirsute on the lobes with white tector hairs; lobes 0.5–1 mm long, narrowly triangular to triangular; standard petal reflexed, 9–11× 6–8 mm, orbicular, apex acuminate, externallY pubescent, claw 3.5–4.5× 0.7–1.5 mm, internallY pubescent; wing petals 7–8× 3.5–4.5 mm, oboVate, claw 2–2.5 mm long; keel petals 8–9× 3–4 mm, stronglY falcate, claw 2–2.5 mm long; stamens 10–12 mm long, anthers elliptical; gYnoecium 11–13 mm long; ovary 4–6 mm long, pubescent, 6–10-ovulate. Hemicraspedium 13–30 mm long, straight to slightly falcate, light brownish, pilose to pubescent, sparse stiff setules at the centre of each article, fruit with (2–)6–8(–11) articles, these 3.5–4× 4–4.5 mm, lenticular. Seeds greY, 2× 2 mm, discoid, without an aril.

Distribution and Habitat— The species is endemic to Argentina, occurring from Río Negro to San Juan and San Luís, but most frequently in Mendoza ( Fig. 27 ). It grows in high elevation vegetation, lowland open grasslands, and sometimes in shrubby areas.

Phenology— Adesmia retrofracta bears flowers and fruits from September to December.

Conservation status— Least Concern (LC). With an EOO of 249.566, 566 km ² and an AOO of 64 km ², Adesmia retrofracta does not qualify for any threatened categories of the IUCN Red List (2019). The low AOO is probably due to the sparse sampling. The conservation status of the species was recently assessed as Least Concern in a detailed study of the threat level of Argentinian endemic species ( Salariato et al. 2021).

Etymology— From Latin “ retro ” back; “ fractus ” broken; referring to the reflexed orientation of the standard petal.

Notes— Adesmia retrofracta is easily confused morphologically with A. grandiflora by having similar leaves and habitat, but it can be differentiated by its flowers 9–12 mm long with a reflexed standard petal and strongly falcate keel petals, and by its discoid grey seeds (vs. flowers 15–20 mm long with a less reflexed standard petal, not strongly falcate keel petals, and reniform brownish seeds in A. grandiflora ). The two species are closely related in our phylogenetic analyses.

Additional Specimens Examined — ARGENTINA. MENDOZA: Challas, 900 m, 19 October 1907, Osten , C . 5704 (MVFA). NEUQUEN: 07 September 1925, Comber, H. F . 47 (K). RÍO NEGRO: General Roca, 1914-1915, Fischer, W . 87-2 ( K); 57 km al N de Barda del Medio por Ruta Nac. 151, 07 December 1997, Fortunato, R. H . 5707 (K).

Figures

FIGURE 5. Geographical distribution of Adesmia bicolor (Poir.) DC., A. bonariensis Burkart, and A. cordobensis Burkart.

FIGURE 27. Geographical distribution of Adesmia punctata (Poir.) DC., A. retrofracta Hook. & Arn., and A. riograndensis Miotto.