Stryphnodendron gracile Heringer & Rizzini (1966: 105)

Scalon, Viviane Renata, Paula-Souza, Juliana De, Lima, Alexandre Gibau De & Souza, Vinicius Castro, 2022, A synopsis of the genus Stryphnodendron (Fabaceae, Caesalpinioideae, mimosoid clade), Phytotaxa 544 (3), pp. 227-279 : 246

13. Stryphnodendron gracile Heringer & Rizzini (1966: 105) .

— Type: BRAZIL. Minas Gerais, Serra do Cipó, 12 November 1959, Heringer 7361 (lectotype RB00584092 !, designated here, isolectotypes NY!, UB!)

Subshrubs 30–50 cm tall, usually cespitose, bearing a well-developed, woody underground root-like system, very rarely shrubs to 2 m tall. Leaves with (4–)5–8(–9) pairs of pinnae; (5–)7–12 pairs of leaflets; rachis nectaries 4, patelliform; blade chartaceous, margin glabrous, leaflets (6–)8–14(–18) × (2–)4–6(–9) mm, discolor, glabrous on both surfaces, unilateral tuft of trichomes on the lower surface absent. Inflorescences of simple thyrsi; cymulae of usually solitary spikes, sometimes geminate, rarely ternate, vinaceous to reddish. Flowers monoclinous or diclinous, vinaceous. Fruit a follicule, straight, flat-compressed, 6.5–9.5(–11) × 1.5–1.9 cm, valves atrovinaceous to dark-brown.

Nomenclatural Notes: —Heringer & Rizzini (1966) indicated two syntypes for S. gracile , both deposited in RB (RB118804/ Rizzini s.n. and RB121073/ E.P. Heringer 7361). The gathering selected by us as lectotype (Heringer 7361, barcode RB00584092 !) is mounted in two separate sheets, and the one bearing the label corresponds to the lectotype.

Distribution and habitat: —This species occurs on slopes and rocky outcrops, campos rupestres and high altitude campos cerrados of the Serra do Cipó, Minas Gerais state, usually in shallow and rocky soils. The collection Glaziou 14649 reportedly gathered in Barbacena (Minas Gerais) corresponds to a mixed set of S. cristalinae (P) and S. adstringens (G, P and R), thus the distribution of the taxon is still considered restricted to the site of the type collection.

Conservation:—Endangered (EN B1ab(i,ii,iii,iv)+2ab(i,ii,iii,iv)) [AOO= 16.000 km 2, EOO= 279.553 km 2]. Although there are registers of this species in conservation units, its distribution area is very reduced and there are indications that it forms small populations.

Phenology: —This species was collected with flowers from March to June and from September to December, while specimens with fruits were collected in February, April and May.

Selected specimens examined: — BRAZIL. Minas Gerais: Jaboticatubas, Serra do Cipó, km 113, ao longo da Rodovia Lagoa Santa – Conceição do Mato Dentro – Diamantina , 15 April 1972, fr., A.B. Joly et al CFSC1534 ( SP). Santana do Riacho , Serra do Cipó , 24 October 1974, fl., G. Hatschbach 35285 ( MBM, UEC) .