Timonius eremiticus J.G.Chavez & Banag, 2020

Timonius eremiticus J.G.Chavez & Banag View in CoL , sp. nov. — Fig. 1 View Fig

Timonius eremiticus differs from T.flavescens (Jack) Baker by the leaf texture (membranous to chartaceous vs subcoriaceous in T. flavescens ), number of secondary nerves (2–4 pairs vs (4–)5–6(–8) in T. flavescens ), corolla colour (ivory-white vs yellow in T. flavescens ), staminate inflorescences (bracteate vs obscurely bracteate in T. flavescens ) and flowers (bracteolate vs ebracteolate in T. flavescens ), corollas of pistillate flowers (5-lobed vs 4-lobed in T.flavescens ), fruits (smooth vs strongly 4-angled in T. flavescens ), and pyrene arrangement in cross-section of the fruit (obliquely radiated vs cruciform in T. flavescens ). — Type: J. G. Chavez & S. G. S. Zamudio PL 110 (holo PNH; iso A, CAHUP, FEUH, GB, L 2 sheets, P, PPC, UBT, US, USTH 2 sheets), Philippines, Palawan Island, Puerto Princesa City, Mt Pulgar , alt. ± 1200 m, ♂, 01 Oct. 2017 .

Etymology. The adjectival Latin epithet means ‘living like a hermit’, since this species grows in a secluded habitat within an urbanized area.

Shrubs to trees up to 10 m tall. Branchlets 0.6–1.7 mm broad towards apex, moderately strigose, glabrescent, trichomes 0.05–0.25 mm long. Stipules valvate, triangular to ovate, 2.6–4.3 by 1.4–2.5 mm, slightly 2-ridged, ridges converging toward the apex, outer surface densely to moderately strigose, trichomes 0.05–0.85 mm long, inner surface densely strigose, trichomes ≥ 1 mm long. Colleters present on inner surface of stipules, bracts, bracteoles, sinuses of calyx teeth of both staminate and pistillate flowers. Leaves simple, opposite; petiole 1.5–8.5 by 0.5–1.7 mm, moderately strigose, glabrescent, trichomes 0.05–0.3 mm long; lamina lanceolate or elliptic to oblanceolate, 2–9.5 by 0.5–4 cm, apex attenuate to acuminate or caudate, base cuneate to obtuse, membranous to chartaceous, upper surface glabrous to sparsely strigose, trichomes 0.15–0.5 mm long, lower surface moderately strigose, trichomes 0.1–0.5 mm long; secondary nerves 2–4 pairs; domatia present as tufts of hairs or hairy pockets in axils of secondary nerves. Staminate inflorescences 3–5-flowered; peduncle 8–18.5 by 0.25–0.6 mm, moderately strigose, trichomes 0.05–0.20 mm long; bracts triangular to lanceolate, 0.9–1.75 by 0.8–1.2 mm, outer surface densely to moderately strigose, trichomes 0.08–0.3 mm long, inner surface densely strigose, trichomes 0.1–1 mm long, bracteoles triangular to ovate, 0.4–0.7 by 0.25–0.5 mm, outer surface densely to moderately strigose, trichomes 0.05–0.25 mm long, inner surface densely to moderately strigose, trichomes 0.05–0.1 mm long. Staminate flowers: calyx cupuliform, 4-toothed, outer surface moderately strigose, trichomes 0.05–0.18 mm long, inner surface dense to moderately strigose, trichomes 0.08–0.25 mm long, tube 1.4–2.5 by 0.75–1.25 mm, teeth triangular, 0.1–0.45 by 0.1–0.5 mm; corolla infundibular, ivory-white, 4-lobed, tube 4–8 by 0.5–1 mm, outer surface moderately strigose, trichomes 0.05–0.15 mm long, inner surface glabrous, lobes lanceolate, 2.5–3.5 by 1–1.5 mm, adaxial surface glabrous, abaxial surface moderately strigose, trichomes 0.05–0.25 mm long; stamens 4, anthers elliptic with sagittate base, 2.7–3 by 0.3–0.4 mm, glabrous, filaments 0.5–0.6 mm long, glabrous; pistillodia bifid, unequal, sparsely strigose at base, trichomes 0.1–0.25 mm long. Pistillate inflorescences solitary; peduncle 6.8–20.75 by 0.2–0.5 mm, moderately to sparsely strigose, trichomes 0.05–0.3 mm long; bracts triangular to lanceolate, 0.4–0.75 by 0.25–0.4 mm wide, outer surface densely to moderately strigose, trichomes 0.05–0.38 mm long, inner surface densely strigose, trichomes 0.1–0.4 mm long. Pistillate flowers: calyx tubular to cupuliform, 4- or 5-toothed, outer surface moderately strigose, trichomes 0.05–0.2 mm long, inner surface densely to moderately strigose becoming sparse towards the apex, trichomes 0.1–0.2 mm long, tube 0.4–0.5 by 1–1.25 mm, teeth triangular to ovate, 0.2–0.3 by 0.4–0.5 mm; corolla tubular, ivory-white, 5-lobed, tube c. 4 by 1.25 mm, outer surface moderately strigose, trichomes 0.05–0.20 mm long, inner surface not seen, lobes lanceolate to lance-ovate, 1.5–1.7 by 0.5–1 mm, adaxial surface glabrous, abaxial surface moderately strigose, trichomes 0.05–0.25 mm long; staminodia not seen; hypanthium ovoid to subglobose, 0.75–2.5 by 1.2–2.8 mm, moderately strigose, trichomes 0.05–0.15 mm long; style not seen. Fruits (sub)globose, smooth, neither costate nor tuber- culate, 4.5–5.8 by 4.75–6.4 mm, sparsely strigose, trichomes 0.05–0.15 mm long; calyx crown < 0.5 mm long; schizogenous cavity absent; pyrenes 20–24, falcoid rarely ovoid, 2.75–3.5 by 0.8–1.4 mm, arranged in four double files radiating obliquely in cross-section of the fruit.

Distribution — Timonius eremiticus is known only from the island of Palawan ( Philippines), where it is restricted to Mount Pulgar.

Habitat & Ecology — It grows in the ecotonal area between the closed canopy forest and pygmy vegetation above the rocky summit of Mt Pulgar (c. 1200 m).

Conservation status — Timonius eremiticus is provisionally classified here as Critically Endangered (CR B2ab(iv)) ( IUCN 2017). It has a restricted area of occupancy of < 10 km 2, and occurs in a single locality. Furthermore, climate change may decrease the number of mature individuals, as it is predicted to cause extreme staminate-biased sex ratios in populations of dioecious plants ( Hultine et al. 2016).

Additional specimens examined ( paratypes). THE PHILIPPINES, Palawan Island, Puerto Princesa City, Mt Pulgar, alt. ± 1200 m, ♀, 01 Oct. 2017, J. G. Chavez & S. G. S. Zamudio PL111 ( A, FEUH, L 2 sheets, PNH, US, USTH); ibid., ♂, 01 Oct. 2017, J. G. Chavez & S. G. S. Zamudio PL113 ( CAHUP 2 About CAHUP sheets, FEUH 2 sheets, L 2 sheets, P, UBT, US, USTH 3 sheets) .

Note — The bracts on the staminate inflorescence of T. eremiticus show a variety of positions ( Fig. 1b View Fig ). During the early stage of inflorescence development, the bracts subtend the base of each inflorescence branch, but as the inflorescence branches develop, the bracts are usually positioned on the apex of each inflorescence branch. Furthermore, a fruiting specimen collected in the Laklangua Peak of Mt Matalingahan, Palawan ( D.D. Soejarto et al. 8879, L (L2963270)), closely resembles the newly described species but differs by its leaves that are clustered on the apex of branchlets hindering a safe identification as T. eremiticus .