Weinmannia oxapampana F.Arroyo, 2021

Arroyo, Frank, 2021, Two new species of Weinmannia (Cunoniaceae) from Machu Picchu and Oxapampa, Peru, Phytotaxa 502 (2), pp. 185-190 : 188-190

Weinmannia oxapampana F.Arroyo , sp. nov. ( Fig. 2 ; Tab.2)

Diagnosis:— Similar to W. chryseis Diels (1906: 414) but differing in the leaflet shape (broadly elliptic to ovate in W. oxapampana vs. elliptic-oblong in W. chryseis ), the wingless leaf rachis (vs. winged rachis in W. chryseis ), and the inflorescence length (6.3–17 cm long in W. oxapampana vs. 14–25 cm long in W. chryseis ).

Type:— PERU. Pasco: Provincia Oxapampa , pass before La Suiza, 20 km W of Oxapampa, 10°35’S 75°33’W, 2100–2150 m, 27 December 1983, Smith 5393 (holotype USM, no. 104378!; isotype MO, no. 3507643 [barcode MO-2060756], photo! Image of the isotype available at. http://legacy.tropicos.org/Specimen/64757?tab=images) .

* Data not reported in the protologues (Diels 1906, Weddell 1857) but taken from Harling (1999) or observed in the types at B, COL, G, K, MOL and P.

Shrub 2–3 m tall; branchlets terete to slightly compressed, distally with pubescent to hirsutulous indumentum, becoming glabrous with age. Leaves opposite, imparipinnate, 5–7-jugate, 3.8–8 cm long; lateral leaflets broadly elliptic to ovate, 7–35 × 6–20 mm, with apex rounded, obtuse or acute, rarely emarginate, margin crenate-serrate to coarsely serrate, base inequilateral; terminal leaflet shorter than laterals, ovate to ovate-elliptic, 11–26 × 6–15 mm, with apex obtuse or acute, margin crenate-serrate, base inequilateral; leaflets coriaceous, mostly conduplicate otherwise flat, glabrous and lustrous above, sparsely velvety beneath, more densely tomentose on midrib; midrib impressed above, prominent beneath, secondary veins in 11–16 pairs, secondary and tertiary venation prominulous on both sides; leaf rachis wingless, tomentose to hirsutulous; petioles terete, not winged, 5–17 mm long, pubescent. Stipules elliptic to suborbicular, 11–15 × 10–14 mm, apex rounded, glabrous adaxially, sparsely pubescent abaxially, caducous. Pseudoracemes 6.3–17 cm long, rachis hirsutulous, fascicles 2–5-flowered, bracteoles ovate, obovate or suborbicular, 1–2 mm long, externally pubescent; pedicels 2–3 mm long, pubescent; calyx lobes 4–5, ovate, 1–1.5 mm long, pubescent, apex acute; petals 4–5, elliptic, 2–2.5 × 1–1.5 mm, glabrous, entire; stamens 8 or 10, 2– 4 mm long; ovary ovoid, glabrous, 1–1.5 mm long, styles 1–1.8 mm long. Capsules septicidal, ovoid-oblong, 3–5 × 1.5–2.5 mm, glabrous, styles persistent, 1–2 mm long; seeds not seen.

Notes:— Weinmannia oxapampana shows morphological affinity with W. chryseis (from northern Peru), in the shrubby habit, leaves velvety beneath and a similar number of coriaceous leaflets per leaf. However, the wingless rachis, the conduplicate leaflets, the shorter inflorescences and the glabrous ovary in W. oxapampana and other features allow to distinguish this species. Weinmannia trianaea Weddell (1857: 211) (from Costa Rica, Colombia and Ecuador), can also have unwinged rachises, but this feature is not constant even on leaves of the same branchlet. However, the ovate and conduplicate leaflets, the pubescent calyx and the elliptic petals of W. oxapampana set it apart from W. trianaea . These three species are compared in Table 2.

Phenology:— Flowering and fruiting reported in October and December.

Distribution, ecology and conservation status: — Weinmannia oxapampana occurs in humid montane forests in the western part of Oxapampa Province, in the region of Pasco, (central Peru), at 2100–3000 m of elevation. The montane forests where this species grows are mostly unprotected, with deforestation for agricultural purposes being the main threat in this area. The National Park of Yanachaga-Chemillen is 3 km from the locality of Perea et. al 0836, and therefore it is expected that this species may also occur there.As it is known from only two localities and its habitat is threatened, the IUCN category of Endangered (EN) is assigned.

Etymology:— The species epithet refers to the province of Oxapampa. region of Pasco, where the type specimen was collected.

Additional specimens:— PERU. Pasco: Provincia Oxapampa, Distrito Huancabamba, Lanturachi , sector Santa Barbara , alrededor del campamento a Milpo , 10°22’ S 75°36’W, 3000 m, 22 October 2003, Perea et al. 0836 (AMAZ, HUT, MO photo!, MOL, USM) .

Figures

FIGURE 2. Weinmannia oxapampana (original drawing from the isotype). A. Fruiting branchlet. B. Leaf. C. Abaxial side of leaf. D. Flower (petal removed to show pistil and some stamens). E. Petal. F. Fruit.