Pholidostachys synanthera (Mart.) Moore (1969: 231)

Henderson, Andrew, 2012, A revision of Pholidostachys (Arecaceae), Phytotaxa 43, pp. 1-48 : 16

7. Pholidostachys synanthera (Mart.) Moore (1969: 231) .

Geonoma synanthera Martius, 1823 –1837: 13. Calyptrogyne synanthera (Mart.) Burret, 1930: 137 . Calyptronoma synanthera (Mart.) Bailey, 1938: 166 . Type:— PERU. Huánuco: Chicoplaya, no date, H. Ruíz & J. Pavón s. n. (holotype M n.v., isotype F!).

Stems 3.3(1.0–6.0) m long, 5.6(3.0–22.0) cm diameter, solitary. Leaves 15(4–27) per stem; sheaths 32.8(15.0–74.0) cm long; petioles 70.1(24.0–136.0) cm long; rachises 84.0(48.0–124.0) cm long, 8.1(3.6– 12.6) mm diameter; pinnae 10(4–18) per side of rachis; basal pinna 49.6(26.5–67.5) cm, long, 1.7(0.2–7.6) cm wide, forming an angle of 50(27–72)° with the rachis; apical pinna 45.0(23.0–65.0) cm long, 10.5(2.5–22.5) cm wide, forming an angle of 15(9–24)° with the rachis. Inflorescences branched 1–2 orders, with a welldeveloped peduncle and rachis, and several rachillae, these spreading at anthesis; prophylls and peduncular bracts woody, not covering rachillae at anthesis; prophylls 38.0(25.5–55.0) cm long; peduncular bracts 32.1(19.0–41.0) cm long, inserted 8.6(5.0–12.5) cm above the prophyll; peduncles 44.8(20.0–70.0) cm long, 11.4(5.3–19.1) mm diameter; rachilla 12(4–25), 28.5(14.0–56.0) cm long, 6.1(3.7–10.3) mm diameter; proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved fruits scarcely compressed, ellipsoid, with obscure longitudinal ridges, 14.3(10.2–17.7) mm long, 8.4(6.1–10.5) mm diameter.

Taxonomic notes. Pholidostachys synanthera is the most widespread species in the genus.

Subspecific variation. There are three geographically separate populations of Pholidostachys synanthera . One occurs at 146(90–250) m elevation in the western Amazon region; the second on eastern Andean slopes at 1040(400–1620) m elevation; and the third on the Cordilleras Central and Oriental in Colombia at 1206(550–1750) m elevation. Only three variables (rachis length, number of divisions, apical pinna angle) are significantly different between the two Andean populations (t -test, P <0.05), and they are here treated as one. Between this expanded Andean population and the Amazon population, 11 variables (stem height, stem diameter, leaf number, rachis length, rachis width, number of divisions, basal pinna length, basal pinna angle, apical pinna length, apical pinna width, rachillae width) are significantly different (t -test, P <0.05). Most of these variables are from stems and leaves, and only one from inflorescences. Based on these results, Amazon and Andean populations are recognized as subspecies (subspp. robusta , synanthera ).