Adesmia securigerifolia Herter, Candollea

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 : 54

17. Adesmia securigerifolia Herter, Candollea 10: 87 (1946).

Type:— URUGUAY. Durazno: Villasboas, in Campis , 07 November 1899, {fl./fr.}, Osten , C. 3892 (holotype: G barcode G00364553 [photo!]; isotype SI barcode 004026 [photo!]) .

Prostrate to ascendant subshrubs, adventitious roots from stem branch nodes absent. Stem pilose, long ochraceous glandular setules on all plant parts. Stipules 3.4–5.5× 1.8–3.3 mm, deltate to lanceolate, pilose to glabrous. Leaves with 3–5 pairs of leaflets; petiole 0.3–1.5 cm long, rachis 0.4–2 cm long, pilose; leaflets 2.5–13× 1–6 mm, elliptic to obovate, apex retuse, base acute, margin entire, pilose. Solitary axillary flowers from the base of the stem to the apex; bracts absent; pedicel 3.5–24 mm long, pilose. Flowers 5.7–6.9 mm long; calyx 3–4 mm long, externally pilose, internally hirsute on the lobes with white tector hairs; lobes 1.1–1.8 mm long, narrowly triangular to linear; standard petal slightlY curVed to reflexed, 6–7× 4–5.5 mm, orbicular to wide-oboVate, apex obtuse to emarginate, externallY glabrous, claw 2.2–3.1× 0.7–1.2 mm, internallY pubescent; wing petals 5.1–7.4× 1.3–2 mm, oboVate, claw 2.2–2.7 mm long; keel petals 4.6–5.7× 1.9–2.6 mm, falcate, claw 1.5–3 mm long; stamens 4.6–7.1 mm long, anthers orbicular; gynoecium 5.5–7 mm long, ovary 2.5–4 mm long, hirsute, 3–5-ovulate. Lomentum 5.6–19.3 mm long, recurved, light brownish to black, pilose, stiff ochraceous setules at the centre of each article, fruit with 3–5 articles, these 3.4– 4.4× 3.2–4.7 mm, triangular. Seeds speckled, blackish, 2.1–2.7× 2.1–2.6 mm, reniform to slightlY triangular, without an aril. ( Figures 20 J–M , 29 A and 30 ).

Distribution and Habitat— Adesmia securigerifolia occurs mainly in Uruguay, in eastern Entre Ríos in Argentina, and near the border in the south of Rio Grande do Sul, Brazil ( Fig. 31 ). It occurs in open grasslands.

Phenology— Flowering from September to October, and fruiting from October to November.

Conservation status— Least Concern ( LC). Adesmia securigerifolia has an EOO of 132.450, 467 km ², and an AOO of 80 km ². The species occurs in many locations in Uruguay , as well as occurring sporadically in Rio Grande do Sul state in Brazil and in the Entre Ríos province of Argentina .

Etymology— The epithet securigerifolia comes from the resemblance of the leaves with species of Securigera de Candolle (1815: 609) , another genus of Leguminosae – Papilionoideae from the Old World, related to Coronilla Linnaeus (1753: 742) .

Notes— Adesmia securigerifolia morphologically resembles A. bonariensis Burkart and A. smithiae DC. due to the presence of solitary axillary flowers, a prostrate habit, and remarkably retuse leaflets ( Fig. 29–30 ). The species is diagnosed by its lomentum with triangular articles (vs. a hemicraspedium with orbicular articles in A. bonariensis , and discoid articles in A. smithiae ), as well as a difference in distribution range, being restricted to Uruguay and nearby regions (Entre Ríos in Argentina and Rio Grande do Sul in Brazil).

Additional Specimens Examined — BRAZIL. RIO GRANDE DO SUL: Bagé, 3 km Oeste do Rio Santa Maria, ao longo da rodovia de Bagé para Dom Pedrito , 06 September 1986, Valls, J. F. M . et al. 10283 ( UEC 55204 ); 01 December 1992, Bastos, N. R . s/n ( PACA 109625 ); 13 km de Bagé para Serrilhada , 10 December 1982, Valls, J. F. M . 6972 ( HAS 27111 ); 24 km de Bagé para Serrilhada , 08 December 1990 Machado, L. A. Z . 713 ( SMDB 3744 ); 10 km de Bagé para Serrilhada , 08 December 1990, Machado, L. A. Z . 697 ( HAS 3743 ). Dom Pedrito , 01 November 1981, Bueno, O . 3296 ( HAS 13888 ). Santana do Livramento , 5 km de Santana do Livramento, 16 October 1979, Mattos, J . 19452 ( HAS 84510 ) . URUGUAY. Durazno: ruta 6 a 26 km de Sarandi del Yi hacia Rincón de Ramirez , 16 December 1993, Brescia, R . & Bayce , D. s/n ( MVFA 24012 ) . Lavalleja: ruta 8, km 166, 14 November 1996, Izaguirre, P . et al. s/n ( MVFA 32966 ) . Río Negro, en base de barranca Greco, Ruta 20, km 106.5, Estancia San José, 24 October 1997, Marchesi, E . & Vignale , M . s/n ( MVFA 27050 ) . Rivera: Estancia Los Ombúes, Minas de Corrales , 12 October 1996, Bayce, D & Davies, P . s/n ( MVFA 25933 ) .

Figures

FIGURE 20. A–C. Adesmia punctata (Poir.) DC. D–F. Adesmia miottoae Cobra, Iganci & Fort.-Perez. G–I. Adesmia riograndensis Miotto. J–M. Adesmia securigerifolia Herter. N–P. Adesmia muricata (Jacq.) DC. A. Pedicel of rare axillary flower; narrow-triangular stipules. B. Detail of branch showing long glandular trichomes, with secretion at their tip. C. Hemicraspedium. D. Detail of the calyx indumentum; short glandular trichomes intermixed with adpressed tector trichomes. E. Calyx opened out, inner surface; lobes longer than the tube. F. Hemicraspedium; calyx persistent with lobes twice as long as the tube. G. Paripinnate leaf with six pairs of opposite leaflets. H. Leaflet with a retuse apex. I. Long-pedicellate fruit; muriculate with stiff glandular trichomes. J. Solitary flower from a leaf axil; deltate stipules; calyx lobes shorter than the tube. K. Detail of the calyx indumentum; long glandular trichomes and short tector trichomes adpressed. L. Long-pedicellate lomentum, muriculate with stiff glandular trichomes. M. Reniform seed, without aril. N. Paripinnate leaf with eight pairs of opposite leaflets. O. Orbicular leaflet with retuse apex. P. Long-pedicellate hemicraspedium, with eight muriculate articles. (Illustration:Klei Souza; Vouchers:A–C: Bastos, N. R. s/n; D–F:Valls, J. F. M. et al. 10812; G–I: Valls, J. F. M. et al. 11930; J–M: Bastos, N. R. s/n; N–P: Valls, J. F. M. et al. 10289).

FIGURE 29. A. Adesmia securigerifolia Herter. B–D. Adesmia subnuda (A. Gray) Burkart. A. Habit prostrate, with axillary solitary yellow flowers from the leaf axils. B. Front view of flowers, dark brownish nectar guides at the centre of the standard petal. C. Side view of flowers; calyx lobes shorter than the tube. D. Leaf with obovate leaflets with a dentate apex. (Photos: A. Rafael Tosi, B–D. Ruth Ripley).

FIGURE 30. Adesmia securigerifolia Herter. A. Leaf with five pairs of obovate leaflets with retuse apices. B. Leaflets abaxial surface glabrous, sparse glandular trichomes on the main vein and the apex. C. Leaflet upper half abaxial surface; sparse glandular trichomes on the main vein and the apex. D. Flower; calyx lobes shorter than the tube. E. External indumentum of long ochraceous glandular trichomes on the calyx. F. Lomentum with rounded-triangular pilose articles. G. Lomentum article with glandular trichomes with a stiff black base at the centre of each article. H. Glandular trichomes with a stiff black base at the centre of the fruit article. (Voucher: all Valls, J. F. M. 13123).

FIGURE 31. Geographical distribution of Adesmia securigerifolia Herter and A. smithiae DC.