Stryphnodendron barbatulum Rizzini & Heringer (1987: 449)

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 : 235

2. Stryphnodendron barbatulum Rizzini & Heringer (1987: 449) .

— Type: BRAZIL. Distrito Federal, Brasília, Barragem do Torto , 14 September 1985, Salles & Heringer 241 (holotype RB 288833!)

= Stryphnodendron sallesianum Heringer & Rizzini ( Rizzini & Heringer 1987: 450) .— Type: BRAZIL. Distrito Federal, Brasília, Barragem do Torto , 11 November 1985, Salles 388 (holotype RB 288834!, isotype RB!). Syn. nov.

Shrub 40–70 cm tall. Leaves with 5–9 pairs of pinnae; 5–11 pairs of leaflets; rachis nectaries 1–2, verruciform; blade usually chartaceous, margin sparsely puberule at least near the base and at the apex, leaflets 1.5–2.9(–3.5) × 1.2–2(–2.5) cm, discolor to rarely subconcolor, upper surface glabrous, lower surface sparsely puberule with a denser indumentum along the midrib, near the base and the apex, unilateral tuft of trichomes on the lower surface present. Inflorescences of simple thyrsi; cymulae of usually solitary spikes, rarely geminate, vinaceous. Flowers diclinous, vinaceous. Fruit a follicule, straight, flat-compressed, valves dark-brown ( Fig. 2B ).

Remarks: — S. barbatulum and S. sallesianum were originally treated as distinct taxa based only in the type collection, but the analysis of new specimens revealed many intermediary characteristics mainly in respect to pinnae number and size, and with identical follicle fruits. Based on this, S. sallesianum is considered a synonym.

Distribution and habitat: —This species is only known from the type locality, region of Granja do Torto, Brasília (Federal District), where it occurs in cerrado areas.

Conservation: —Critically Endangered (CR B2ab(ii,iii)) [AOO= 4.000 km 2, EOO not measurable]. Although the reduced size of the individuals makes it difficult to visually estimate the size of the populations, the species occurs in an area that has received considerable collecting efforts in the last decades. However, there are no recent collections of this taxon and recent visits to the region revealed a very small fragment of remaining native vegetation, though not occupied by residences, but taken by ruderal plants. The area is indisputably under extreme anthropogenic pressure, and thus Stryphnodendron barbatulum is here considered Critically Endangered.

Phenology: —Flowering samples of this species were collected in September and November, fruiting samples were collected in February.

Figures

FIGURE 2. Subshrub species of Stryphnodendron. A. Stryphnodendron heringeri Occhioni f.; B. Stryphnodendron barbatulum Rizzini & Heringer; C. Stryphnodendron platyspicum Rizzini & Heringer; D. & E. Stryphnodendron cristalinae Heringer, the woody underground root-like system in detail.