Adesmia muricata DC., Ann. Sci. Nat. (Paris

11. Adesmia muricata (Jacq.) DC., Ann. Sci. Nat. (Paris) 4: 95 (1825a).

Type:— ARGENTINA. Patagonia, s/d, {fl./fr.}, s/c (lectotype, designated here: Icon. Pl. Rar. [Jacquin] 3(16): pl. 568 (1795)).

≡ Hedysarum muricatum Jacq., Icon. Pl. Rar. [Jacquin] 3(16): 13, pl. 568 (1795).

≡ Patagonium hedysaroides Schrank, Denkschr. Königl. Akad. Wiss. München 1: 93 (1808). nom. superfl. illegit., based on Hedysarum muricatum Jacq.

≡ Patagonium muricatum (Jacq.) Kuntze, Revis. Gen. Pl. 1: 200 (1891).

≡ Adesmia hedysaroides (Schrank) Hauman, Anales Soc. Ci. Argent. ser. 3 24: 398 (1913). nom. superfl. illegit.

= Adesmia muricata var. rionegrensis Burkart, Darwiniana 10(4): 475–476 (1954). syn. nov.

Type:— ARGENTINA. Rio Negro: estae Río Negro (hoy General Roca), 05 January 1915, {fl./fr.}, Fischer, W. 87 (holotype: SI barcode 001584 [photo!]; isotypes: US barcode US 00385589 [photo!]; BM barcode BM000931720 [photo!]).

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

Type:— ARGENTINA. Bahia Blaca, s.d. {fl.}, Darwin, C . 91 (holotype: K barcode K000327943!).

≡ Patagonium affine (Hook.f.) Macloskie, Rep. Princeton Univ. Exped. Patagonia, Botany 8: 511 (1905).

≡ Adesmia muricata var. affinis (Hook.f.) Burkart, Darwiniana 10(4): 473–475 (1954). syn. nov.

= Patagonium muricatum var. incanum Kuntze, Revis. Gen. Pl. 3(3): 70 (1898).

Type:— ARGENTINA. Jujuy: (holotype not found).

≡ Adesmia muricata var. incana (Kuntze) Burkart, Darwiniana 3(2): 326 (1939).

Ascendant to erect shrubs or subshrubs, adventitious roots from stem branch nodes absent. Stem pilose to glabrous, with a variable density of white tector hairs and ochraceous glandular setules on all plant parts. Stipules 2–4× 1–2 mm, narrowly triangular to wide-lanceolate, pilose to glabrescent. Leaves with (4–)5–7(–8) pairs of leaflets; petiole 0.3–2.2 cm long, rachis 0.9–4.7 cm long, pilose to pubescent; leaflets 3–13× 1–6 mm, elliptic to oboVate, apex truncate to obtuse, base acute, margin entire to rarely dentate, pubescent to glabrous on both surfaces. Raceme terminal, up to two axillary flowers below the inflorescence, (4–) 10–60 cm long, pilose to hirsute; bracts 1–4 mm long, triangular to lanceolate, pilose to pubescent; pedicel straight after anthesis, 3–28 mm long, pilose to hirsute. Flowers 6.7–9 mm long; calyx 3.5–5 mm long, externally pilose to pubescent, internally glabrous; lobes 1.2–2.5 mm long, narrowly triangular to triangular; standard petal reflexed, 6–7× 6–7 mm, orbicular to flabelliform, apex obtuse; externallY pubescent, claw 1.5–2× 0.8–1.3 mm, internallY pubescent; wing petals 5.5–7× 2–3 mm, oboVate, claw 2–3 mm long; keel petals 4.5– 6× 2–3 mm, falcate, claw 2–2.5 mm long; stamens 5.5–7 mm long, anthers elliptical; gYnoecium 7–8.5 mm long, oVarY straight, 3.5–4.5 mm long, pubescent, (7–)8–9-ovulate. Hemicraspedium 13–24 mm long, straight or curved, light brownish, pilose to muricate, stiff ochraceous setules at the centre of each article, fruit with (6–)8–9(–10) articles, these 1.5–2.5× 1.5–3 mm, orbicular. Seeds brownish, 1–1.5× 1–1.3 mm, orbicular, without an aril. (Figures 20 N–P and 22).

Distribution and Habitat— The species occurs from the south of Rio Grande do Sul state, in Brazil, extending to Uruguay and the provinces of Buenos Aires, Entre Ríos, and Río Negro, in Argentina (Fig. 21). It is a typical species of the Pampean grasslands.

Phenology— Flowers from September to December and fruits from October to December.

Conservation status— Least Concern (LC). Adesmia muricata has an EOO of 278.789, 922 km ² and an AOO of 40 km ². Even though the species suffers from pasture agricultural use, it is widely distributed in Argentina, and extends into Uruguay and Brazil. The species occurs in several different locations and is thus not threatened.

Etymology— The epithet comes from “ mūrex”, muricate means rough with small hard protuberances, this referring to the surface of the hemicraspedium articles.

Notes— Adesmia muricata is a typical Pampean species, recognized by its leaf and fruit characters (Fig. 20, 22). The species has a wide geographical distribution and is morphologically variable, which has led to the recognition of several infraspecific taxa in previous studies. Burkart (1954) recognised A. muricata var. affinis (Hook.f.) Burkart, A. muricata var. dentata (Lag.) Benth., A. muricata var. gilliesii (Hook. & Arn.) Burkart, and A. muricata var. rionegrensis Burkart. Of these four varieties, A. muricata var. rionegrensis and A. muricata var. affinis, in particular, show a large overlap in morphology and distribution.

Adesmia muricata var. rionegrensis was differentiated from the typical variety only by the absence of glandular trichomes on its leaflets. Adesmia muricata var. affinis, in turn, was distinguished by its fistulose stem, more robust habit, and by its leaflets 5–14 mm long (vs. stem not fistulose, a herbaceous habit, and leaflets 3–8 mm long in A. muricata var. muricata). We observed that the abundance of glandular trichomes vary according to environmental conditions, such as temperature and predatory pressures. We also found that the morphological characters used to differentiate A. muricata var. affinis overlap with those of the typical variety. In consequence we synonymize A. muricata var. affinis and A. muricata var. rionegrensis under A. muricata var. muricata.

On the other hand, Adesmia gilliesii is morphologically distinct and geographically disjunct from A. muricata. Adesmia muricata has leaflets with an entire to dentate margin, and an eastern distribution from the Río Negro province in Argentina north to southern Rio Grande do Sul state, Brazil (vs. lobate leaflets and an occurrence restricted to central Argentina – Cordoba, La Pampa, Mendoza).

Adesmia muricata var. dentata, based on A. dentata (Lag.) DC., was a superfluous name when published, and is treated as a synonym of A. pimpinellifolia in this study. Adesmia pimpinellifolia was recognized as a variety of A. muricata by Burkart (1966). However, the species is distributed along the Andean mountains from northern Argentina to southern Peru, and usually has its leaflets lobed to dentate, and 3–8 mm wide (vs. leaflets with the margin entire to dentate, and 1–6 mm wide in A. muricata).

Regarding typification, Hedysarum muricatum was described by Jacquin (1795), based on a cultivated specimen in a European botanical garden. However, there are no preserved specimens in herbaria that were used to describe the species, and its recognition is linked directly to Jacquin’s description and illustration in the protologue. Ulibarri and Burkart (2000) designated a specimen from the Natural History Museum (BM), London, as a “spermotype” – a specimen resulting from cultivation of seeds from the original plant material. Such a type terminology is not recognized by the 9° article of the Nomenclatural Code (Turland et al. 2018). Following article 9.12° of the Code, we here designate the illustration of Jacquin (Icones Plantarum Rariorum 3(16): p. 568. 1795), as a lectotype.

Additional Specimens Examined — BRAZIL. RIO GRANDE DO SUL: Bagé, BR-153, 29 January 1991, Machado, L. A. Z . 1616 (SMDB 3754). Caçapava do Sul, Serra de Santa Bárbara, BR-392, 08 October 1989, Machado, L. A. Z . 236 (SMDB 3755); Vila Progresso, BR-290, 01 October 1990, Machado L. A. Z . 631 (SMDB 3757); Pontas do Santa Bárbara, Cerro do Bugio, 02 November 1989, Machado L. A. Z . 328 (SMDB 3756). URUGUAY. 1987, Gilbert 739 (K). FLORIDA: Cerro Colorado, 03 October 1945, Rosengurtt, B . et al. PE-5059 (PACA 33585). MONTEVIDEO: Pajas Blancas, 06 October 1935, Herter, W. G. F . 96620 (U 1245685 [photo!]). SORIANO: 13 October 1940, Rosengurtt, B . et al. PE-4412 (U 1245683 [photo!]). TACUAREMBÓ: Valle Eden, 29 September 1928, Herter, W. G. F . 83703 (U 1245687 [photo!]).