11) Macropsychanthus umbrinus (Elmer) L.P. Queiroz & Snak, PhytoKeys 164: 104, 2020.

Dioclea umbrina Elmer, Leafl. Philipp. Bot. 1: 224. 1907.

Type: Philippines, Leyte, January 1906, Elmer 7249 (holotype: PHN; isotype: K-000898375!). Fig. 14.

Diagnostic description. Lianas with fulvous indumentum overall, and canescent indumentum on the inflorescence. Leaflets with smooth surfaces and 8–11 pairs of secondary veins. Flowers 1–1.5 cm long, calyx with four lobes, ten fertile stamens. Legume 10–12 cm long × 4–4.5 cm wide × 1.5–2 cm thick, fulvous villose, laterally compressed, pedicel attachment displaced toward the dorsal suture. Seeds 2–2.5 cm long × 1.5–2 cm wide × 1–1.5 cm thick, orbicular in outline, brown, smooth.

Etymology. The specific epithet derives from the Middle French word “umbre” meaning “brown”, likely referring to the color of the fruit indumentum.

Distribution and habitat. Macropsychanthus umbrinus is endemic from the Philippines, where it occurs in humid and riverine forests (Fig. 2E).

Preliminary conservation assessment. The Extent of Occurrence (EOO) is estimated as 639,904 km ², which greatly exceeds thresholds for a threatened category under criterion B1. The Area of Occupancy (AOO) is estimated as 56 km ², which meets the threshold for Endangered (EN) under criterion B2 (AOO <500 km ²). The species is threatened by deforestation due to logging, shifting agriculture, and clearance for settlements (Curtis et al., 2018, Wikramanayake 2025). This threat is inferred to be contributing to a continuing decline in the area and quality of habitat for this species. It is known from 14 locations, barely exceeding the threshold for a threatened category. Since this species nearly meets all of the subcriteria for a threatened category under criterion B2, but occurs at more than 10 locations, we propose classifying this species as Near Threatened B2ab(iii) according to IUCN criteria (2024).

Comments. This species could be confused with M. hexander due to similarities in leaflet morphology, shared indumentum type, and the number of secondary veins. However, M. umbrinus can be distinguished by its canescent indumentum on the inflorescences, smaller flowers (1–1.5 cm long), ten fertile stamens, villose pods, and orbicular in outline seeds. In contrast, M. hexander has fulvous indumentum on the inflorescences, larger flowers (2–2.5 cm long), six fertile stamens and four staminodes, strigose pods, and laterally compressed, D-shaped seeds.

Specimens examined. PHILIPPINES, Laguna, Los baños (Mt. Maquiling). Island of Luzon, June–July 1917, Elmer 17865 (US, P, L, U); Leyte, Palo, Leyte, 1828, Elmer 7249 (K); Luzon, San Mariano, Isabela province, February– March 1926, Ramos & Edaño 46734 (P); Luzon, Manille, w.d., Cumming 521 (P); Luzon, Batigui Promontory, Batangas Province (S.E.), December 1950, Sulit 13832 (L); Luzon, Bapuio, Mar 1907, Elmer 8922 (K); Luzon, Calauan, prov. of Laguna, November–December 1910, McGregor 12394 (K); Luzon, Antipolo, Province of Rizal, November 1914, Ramos 22257 (K, L, US); Luzon, Antipolo, Prov. Rizal, March 1903, Elmer 1621 (US); Luzon, Province of Rizal, January 1911, Ramos 708 (US, U, SI, U); Mindanao, Todaya (mt. Apo), District of Davao, October 1909, Elmer 11905 (L, U, US, WRSL); Mindoro, Naujan, November–December 1925, Ramos 46455 (P); Palawan, Silanga, May 1913, Merrill 9595 (US, K); Palawan, Balabac Island, November 1927, Ramos & Edaño 49804 (BR); Panay, Jamindan, Capiz province, April–May 1918, Ramos & Edaño 31387 (US, P); Samar, Catubig river, February–March 1916, Ramos 24168 (US); THAILAND. Chonburi, Si Racha, 20 December 1907, Collins 1821 (US).