Pholidostachys occidentalis Henderson, Phytotaxa 43: 12 (2012)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
From 3°43S'-6°45'N and 76°02'-79°46'W in western Colombia and western Ecuador at 854(300-1600) m elevation in lowland or montane rainforest (Henderson, A.J., A revision of Pholidostachys (Arecaceae) in Phytotaxa 43. 2012)A

Discussion

  • Borchsenius et al. (1998) were the first to point out the differences between populations of Pholidostachys synanthera from west and east of the Andes. The western population, here recognized at the specific level as P. occidentalis, has inflorescences that are branched to 1 order and have elongate peduncles, short rachises, and several rachillae that are pendulous at anthesis (versus P. synanthera with inflorescences that are branched 1-2 orders and have well-developed peduncles and rachises, and several rachillae that are spreading at anthesis). The fruits of the two species also differ. Pholidostachys occidentalis has compressed fruits, obovoid in lateral view with an asymmetric base, ellipsoid in frontal view, with a pronounced longitudinal ridge on one side and several lesser ridges on the opposite side. Pholidostachys synanthera has scarcely compressed fruits that are ellipsoid with obscure longitudinal ridges.

    Subspecific variation. Pholidostachys occidentalis occurs in scattered localities from southwestern Ecuador to northwestern Colombia, but there are too few specimens to test for differences amongst these populations. Like P. dactyloides, this species has an unusually wide range in elevation. (Henderson, A.J., A revision of Pholidostachys (Arecaceae) in Phytotaxa 43. 2012)A

Description

  • Stems 5.4(2.5-11.0) m long, 10.4(7.0-15.0) cm diameter, solitary. Leaves 15(12-20) per stem; sheaths 25.3(16.0-40.0) cm long; petioles 51.7(45.0-60.0) cm long; rachises 192.0(150.0-234.0) cm long, 16.3(7.8-24.4) mm diameter; pinnae 12(8-13) per side of rachis; basal pinna 47.4(34.0-83.0) cm, long, 3.9(1.4-10.0) cm wide, forming an angle of 54(34-67)° with the rachis; apical pinna 42.9(34.0-54.0) cm long, 18.5(10.0-25.5) cm wide, forming an angle of 25(18-29)° with the rachis. Inflorescences branched 1 order, with an elongate peduncle, short rachis, and several rachillae, these pendulous at anthesis; prophylls and peduncular bracts woody, not covering rachillae at anthesis; prophylls 62.0 cm long; peduncular bracts 59.0 cm long, inserted 7.8(4.0-11.5) cm above the prophyll; peduncles 114.1(72.0-171.0) cm long, 10.1(6.3-12.5) mm diameter; rachilla 8(6-11), 50.8(33.0-64.0) cm long, 7.4(6.3-8.6) mm diameter; proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved; fruits compressed, obovoid in lateral 13 view with an asymmetric base, ellipsoid in frontal view, with a pronounced longitudinal ridge on one side and several lesser ridges on opposite side, 17.0(16.2-18.0) mm long, 9.3(8.5-9.8) mm diameter. (Henderson, A.J., A revision of Pholidostachys (Arecaceae) in Phytotaxa 43. 2012)A