Pholidostachys panamensis Henderson, 2012

Henderson, Andrew, 2012, A revision of Pholidostachys (Arecaceae), Phytotaxa 43, pp. 1-48 : 13

4. Pholidostachys panamensis Henderson , sp. nov. (Appendix IV, Plates 9–14)

It differs from other species in its spicate inflorescences and widely obovoid fruits without pronounced longitudinal ridges.

Type:— PANAMA. Coclé: Continental Divide above El Copé , 8°38’N, 80°39’W, 650–750 m, 27 November 1985, G. de Nevers, A. Henderson, H. Herrera, G. McPherson & L. Brako 6371 (holotype NY!, isotype MO!) .

Stems 1.1(0.1–3.0) m long, 7.4(4.0–11.0) cm diameter, solitary. Leaves 12(8–19) per stem; sheaths 21.5(15.0–27.0) cm long; petioles 102.1(36.0–150.0) cm long; rachises 126.1(72.0–155.0) cm long, 8.8(6.1– 11.1) mm diameter; pinnae 6(5–8) per side of rachis; basal pinna 52.8(28.5–78.0) cm, long, 5.2(0.7–10.0) cm wide, angle with the rachis no data; apical pinna 42.4(32.5–49.5) cm long, 18.0(10.0–27.0) cm wide, forming an angle of 17(10–28)° with the rachis. Inflorescences spicate, with a short peduncle, absent rachis, and 1 rachilla, this erect at anthesis; prophylls and peduncular bracts fibrous, covering all or part of the rachilla at anthesis; prophylls 15.2(11.5–18.5) cm long; peduncular bracts 20.2(19.0–22.5) cm long, inserted 3.3(2.0– 5.0) cm above the prophyll; peduncles 4.6(3.5–6.2) cm long, 10.0(8.2–13.5) mm diameter; rachilla 1, 13.6(11.5–15.5) cm long, 10.0(8.2–12.1) mm diameter; proximal lips of flower pits regularly shaped, rounded, completely covering pits before anthesis and not recurved; fruits widely obovoid, without pronounced longitudinal ridges, 28.6(22.5–32.1) mm long, 20.8(18.1–24.5) mm diameter.

Distribution and habitat. From 8°34’– 9°25’N and 78°48’– 80°56’W in Panama at 483(60–768) m elevation in lowland rainforest ( Fig. 5 ).

Taxonomic notes. Pholidostachys panamensis differs from other species in its spicate inflorescences and widely obovoid fruits ( Fig. 4C ). See notes on Pholidostachys kalbreyeri under Excluded Names.

Subspecific variation. There are two separate populations of Pholidostachys panamensis , occurring 170 km apart in Panama. Although sample size is small, the western population, on the eastern end of the Central Cordillera, has shorter stems, shorter petioles, and shorter and thinner basal pinnae than the eastern population, on the western end of the Serranía de San Blas. The western population also occurs at a higher mean elevation— 722(695–768) m versus 303(60–450) m.

de Nevers (1995) reported that some specimens have bifid inflorescences, but no such specimens have been seen in the present study.

Figures

FIGURE 4. A. Fruits of Pholidostachys dactyloides (Dodson 14491). B. Fruits of P. occidentalis (Balslev 60678). C. Fruits of P. panamensis (Liesner 1255). D. Fruits of P. pulchra (de Nevers 4285). E. Fruits of P. sanluisensis (Juncosa 726). F. Fruits of P. synanthera subsp. synanthera (Couvreur 119). Scale bar = 1 cm.

FIGURE 5. Distribution maps of Pholidostachys amazonensis, P. dactyloides, P. occidentalis, and P. panamensis.