Stryphnodendron venosum Scalon, 2022

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 : 272-274

35. Stryphnodendron venosum Scalon , sp. nov. ( Fig. 11 )

— Type: BOLÍVIA. Santa Cruz: Ichilo, Reserva Florestal Choré , Rio Ibabo , Bosque Experimental “Elias Meneces”, 180 m, 16°35’S, 64°31’W, 16-18 August 1990, fr., D. Neill & R. Quevedo 9361 (holotype MO 3807891 !, isotypes G!, NY!, U!)

Diagnosis: Stryphnodendron venosum resembles S. porcatum , but differs by the petiolar nectaries verruciform with an elongated base, 3–5 × 1.5–2 mm (vs. verruciform, 1 × 1–1.5 mm in S. porcatum ), 6–9 pairs of pinnae (vs. 11–14 pairs), rachis sparsely ferruginous-pulverulent, glabrescent (vs. yellow-velutinous), leaflets (11–)13–24 × (6–) 7–19 mm (vs. 4–11 × 2–6 mm) and the unilateral tuft of trichomes on the lower surface, not prolonged (vs. bilateral, usually prolonged up to half the blade).

Trees 10–18 m tall, the branches lenticellate, lacking extrafloral nectaries, glabrous to subglabrous, ferruginouspulverulent, glabrescent, densely ferruginous-pulverulent at the apex. Leaves with petioles 4.5–5 cm long, glabrous to sparsely ferruginous-pulverulent, glabrescent, extrafloral nectary 1, inserted at 1–1.5 cm from the base of the petiole, 3–5 × 1.5–2 mm, verruciform with an elongated base; pinnae 6–9 pairs, subopposite to opposite, the insertion of each pair spaced in 1.2–2.2 cm; rachis striate, sparsely ferruginous-pulverulent, glabrescent; extrafloral nectaries 2–3, inserted at 1–3 mm below the distal pair of pinnae, ca. 0.5 × 0.5 mm, verruciform; stipels deciduous, not seen; 2nd degree petiolules ca. 1 mm long, the same color as the upper surface of the blade, puberule; leaflets (6–)8–10 pairs; rachillae very sparsely ferruginous-pulverulent, glabrescent, extrafloral nectaries 3–8, inserted at ca. 1 mm below the distal pair of leaflets, ca. 0.3 × 0.3 mm, verruciform; stipel deciduous, not seen; leaflets usually subopposite, opposite towards the apex of the rachis, very rarely alternate, blade asymmetrical, usually oblong-rhombic, sometimes ovalate, rarely elliptic (especially the proximal pairs of leaflets), the distal pairs usually widely obovate to sometimes obovate, (11–)13–24 × (6–) 7–19 mm, apex usually retuse, sometimes widely rounded, rarely truncate, margin sub-revolute, entire and puberule, base asymmetrical, the proximal side usually obtuse, sometimes truncate, rarely widely rounded, the distal pairs usually acute, distal side narrowly rounded, chartaceous to subcoriaceous, discolor, upper surface nigrescent, sparsely puberule, lower surface lighter, puberule, opaque on both surfaces, unilateral tuft of trichomes on the lower surface of the leaflets present, not prolonged, venation brochidodromous, the nerves weakly evident on both surfaces, the midrib sulcate at the upper surface, prominent at the lower surface, the remaining nerves weakly prominent at the lower surface. Inflorescences of simple thyrsi, color unknown; cymulae not seen; peduncle 1.4–2.5 cm long, densely ferruginous-pulverulent, subcylindrical; floral rachis not seen. Flowers not seen; prophylls early deciduous or deciduous, not seen. Fruit a sessile nucoid legume, curved, apex acute, apiculate, base acute to attenuate, flat-compressed, seeds not prominent and evident, the edges thick, 5.4–8.5 × 1.4–2.5 cm, valves subcoriaceous to coriaceous, dark brown, reddish, ferruginous-pulverulent, glabrescent, conspicuously nerved. Seeds not seen.

Vernacular name: — Crespito, Koshi (Mosetén, Bolivia).

Etymology: —The epithet refers to the conspicuously nerved valves of the fruits.

Remarks: —Among the consulted collections only two specimens could be recognized as Stryphnodendron venosum . Though none of them has flowers as to allow the description of reproductive characteristics, it is still possible to confirm that the Bolivian samples represent a new taxon based on unique features in relation to the morphologically most similar species, S. porcatum , which is only found in Ecuador and differs from the new species by the features listed on table 7.

Distribution and habitat: —This taxon is only registered in humid forests of Central Bolivia, frequently in flooded areas.

Conservation: —Data Deficient (DD) [AOO= 4.000 km 2, EOO not measurable]. The new species is only known from three locations, and although one of them is known to be a conservation unit, we have no information as to the threats in the remaining distribution area.

Phenology: —Flowering materials collected in January, fruiting materials in August.

Additional specimens examined (paratypes): — BOLIVIA. Santa Cruz, Ichilo, Río Ibabo, Reserva Forestal Choré , Bosque Experimental “Elias Meneces”, líneas 3 & 4 del inventario forestal, elev. 180 m, 16°35’S, 64°31’W, 5–10 August 1990, fr., Neill et al. 9231 (G!, K!, MBM!, MO!, NY!, U!) . La Paz: Larecaja, Alto Beni, Concesión de la Cooperativa San Luis, cerca del arroyo Mayaya , 380 m, 28 November 1996, sterile, R. Seidel et al. 8129 (K). Sud Yungas, Alto Beni, Sapecho , 22 January 1997, fl., W. Steiner 1121 (K) .

Figures

FIGURE 11. Isotype of Stryphnodendron venosum Scalon in NY.