Stryphnodendron confertum Heringer & Rizzini (1966: 104)

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 : 235-237

3. Stryphnodendron confertum Heringer & Rizzini (1966: 104) .

— Type: BRAZIL. Distrito Federal. Brasília, Parque Nacional de Brasília , 10 September 1963, Heringer 9178 (holotype RB 118803!, isotypes HB!, K!, M!, NY!, RFA!, UB!)

Subshrubs 50–80 cm tall, usually cespitose, bearing a well-developed, woody underground root-like system. Leaves with 8–11 pairs of pinnae; 10–15(–18) pairs of leaflets; rachis nectaries 2–4, verruciform; blade chartaceous, margin ciliate, leaflets (6–)10–15 × (2–) 4–8 mm, discolor, glabrous on both surfaces, with sparse trichomes along the midrib, unilateral tuft of trichomes on the lower surface absent. Inflorescences of simple thyrsi; cymulae of solitary spikes, vinaceous. Flowers monoclinous, purplish to rarely pinkish. Fruit a follicule, straight, flat-compressed, 5.5–8 × 1.2– 1.4 cm, valves dark-brown.

Distribution and habitat: — S. confertum is endemic to Goiás state and Federal District ( Brazil), in cerrado s.str. or campo cerrado, usually on rocky and / or sandy soil. The area where the holotype was collected in the Federal District, Granja do Torto, is currently a residential district of Brasília, with few areas still unoccupied. Other collections are referred to the Federal District, such as the Santa Maria dam, in a legally protected area (Brasilia National Park). No natural populations of this species were found on recent visits to the species´s known distribution range.

The label of the specimen E.P. Heringer 14748 (UB) reads “cultivated in Brasilia from seeds from the municipality of Cristalina, Goiás state ”. However, duplicates of this collection at HB and MO showed mixed samples of S. confertum and S. cristalinae ), and certainly the label information corresponds to S. cristalinae , which is endemic to Cristalina (see comments of this species). Recent expeditions to Cristalina failed to find any population of S. confertum , reinforcing the distribution of S. confertum to the sites indicated above.

Conservation: —Endangered (EN B1ab(i,ii,iii)+2ab(i,ii,iii) [AOO= 16.000 km 2, EOO = 1,134.284 km 2]. Although natural populations of S. confertum are found within a legally protected area, this species occurs in a restricted and threatened region.

Phenology: —Flowering specimens were collected in June and from September to November, fruiting specimens were collected in May and June.

Selected specimens examined: — BRAZIL. Distrito Federal: Brasília, Granja do Torto, 20 September 1963, fl. E.P. Heringer 9178 ( UB). Brasília, Parque Nacional de Brasília , acesso pela portaria da CAESB, 1km a oeste em direção à represa, 01 June 2015, fr., M.F. Simon 2599 ( CEN) .