Pholidostachys amazonensis Henderson, 2012

Henderson, Andrew, 2012, A revision of Pholidostachys (Arecaceae), Phytotaxa 43, pp. 1-48 : 9-11

Pholidostachys Wendl. ex Hooker 1883

Pholidostachys Wendl. ex Hooker 1883: 915 . Type: Pholidostachys pulchra Wendl. ex Burret

Calyptrogyne subgen. Pholidostachys (Wendl. ex Hooker) Wessels Boer 1968: 73 .

Stems solitary, more rarely clustered, 3.8(0.1–11.0) m long, 6.6(3.0–22.0) cm diameter. Leaves 14(4–27); sheaths 34.7(14.0–110.0) cm long; petioles 73.5(20.0–150.0) cm long; rachises 106.9(32.0–234.0) cm long, 9.6(3.3–24.4) cm wide; pinnae 9(3–18) per side of rachis; basal pinna 50.7(26.5–92.0) cm long, 2.1(0.2–10.0) cm wide, forming an angle of 54(27–93) ° with the rachis; apical pinna 42.7(23.0–65.0) cm long, 13.2(2.5– 27.0) cm wide, forming an angle of 16(7–29)° with the rachis. Inflorescences branched 1 order, with an elongate peduncle, short rachis, and several rachillae, these pendulous at anthesis, or inflorescences branched 1–2 orders, with a well-developed peduncle and rachis, and several rachillae, these spreading at anthesis, or inflorescences branched 1 order (rarely 2 orders), with a well-developed peduncle, short rachis, and several rachillae, these erect at anthesis, or inflorescences spicate, with a well-developed peduncle, absent rachis, and 1 rachilla, this arching or erect at anthesis, or inflorescences spicate, with a short peduncle, absent rachis, and 1 rachilla, this erect at anthesis; prophylls 23.9(5.0–62.0) cm long; peduncular bracts 33.9(12.5–65.0) cm long, the bracts inserted 5.1(1.1–12.5) cm apart; prophylls and peduncular bracts fibrous, covering all or part of the rachilla(e) at anthesis, or prophylls and peduncular bracts woody, not covering rachilla(e) at anthesis; peduncles 25.5(3.5–171.0) cm long, 9.0(3.2–19.1) cm wide; rachillae 5(1–25), 33.3(7.5–85.0) cm long, 7.4(3.7–16.2) mm wide; proximal lips of flower pits regularly shaped, rounded, completely covering pits before anthesis and not or seldom recurved, or proximal lips of flower pits irregularly shaped, often acute or acuminate, completely covering pits before anthesis, or proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved; fruits compressed, 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 opposite side, or fruits compressed, obovoid in lateral view with an asymmetric base, ellipsoid in frontal view, with a pronounced meridional ridge, or fruits scarcely compressed, obovoid, with obscure longitudinal ridges, or fruits widely obovoid, without pronounced longitudinal ridges, or fruits scarcely compressed, ellipsoid, with obscure longitudinal ridges.

Key to the species of Pholidostachys

1 Prophylls and peduncular bracts fibrous, covering all or part of the rachilla(e) at anthesis ....................................... 2

- Prophylls and peduncular bracts woody, not covering rachilla(e) at anthesis ............................................................. 4

2 Inflorescences spicate, with a short peduncle, absent rachis, and one rachilla, this erect at anthesis; central Panama. ................................................................................................................................................................ P. panamensis

- Inflorescences branched 1 order, with a well-developed peduncle, short rachis, and several rachillae, these erect at anthesis; eastern Panama, western Colombia, and western Ecuador........................................................................... 3

3 Fruits 19.8(19.6–19.9) mm long, compressed in lateral view with an asymmetric base, ellipsoid in frontal view, with a pronounced meridional ridge; Colombia (Cordillera Central).............................................................. P. sanluisensis

- Fruits 12.2(8.8–16.3) mm long, scarcely compressed, obovoid, with obscure longitudinal ridges; western Colombia (Cordillera Occidental and Chocó) and western Ecuador......................................................................... P. dactyloides

4 Inflorescences branched 1 order, with an elongate peduncle, short rachis, and several rachillae, these pendulous at anthesis; western Colombia and western Ecuador.................................................................................. P. occidentalis

- Inflorescences branched 1–2 orders, with a well-developed peduncle and rachis, and several rachillae, these spreading at anthesis, or inflorescences spicate, with a well-developed peduncle, absent rachis, and one rachilla, this arching or erect at anthesis .................................................................................................................................................. 5

5 Inflorescences branched 1–2 orders, with a well-developed peduncle and rachis, and several rachillae, these spreading at anthesis ........................................................................................................................................... P. synanthera

- Inflorescences spicate, with a well-developed peduncle, absent rachis, and one rachilla, this arching or erect at anthesis ......................................................................................................................................................................... 6

6 Proximal lips of flower pits completely covering pits before anthesis and not recurved; Nicaragua, Costa Rica, Panama, and Colombia....................................................................................................................................... P. pulchra

- Proximal lips of flower pits not covering pits before anthesis, recurved; Peru..................................... P. amazonensis

1. Pholidostachys amazonensis Henderson , sp. nov. (Appendix IV, Plate 1)

It differs from other species in its spicate inflorescence and proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved.

Type:— PERU. Amazonas: Bagua Province, along roadside from Chiriaco to Puente Venezuela , 43 km (by road) NE of Chiriaco, ca. 1050–2400 ft., 5 November 1978, P. Barbour 4471 (holotype USM n.v., isotype MO!) .

Stems no data. Leaves number per stem no data; sheaths and petioles no data; rachises 42.0 cm long, 3.7 mm diameter; pinnae 6 per side of rachis; basal pinna no data; apical pinna length no data, 3.5 cm wide, forming an angle of 15° with the rachis. Inflorescences spicate, with a well-developed peduncle, absent rachis, and 1 rachilla, this arching at anthesis; prophylls and peduncular bracts woody, not covering rachilla at anthesis; prophylls and peduncular bracts no data; peduncles length no data, 3.2 mm diameter; rachilla 1, 18.7 cm long, 5.9 mm diameter; proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved; fruits no data.

Distribution and habitat. At 4°56’N and 78°10’W in Peru (Amazonas) at medium elevations in lowland rainforest ( Fig. 5 ).

Taxonomic notes. For inflorescence bracts and proximal flower pit shape, Pholidostachys amazonensis shares the same character states as P. synanthera . Fruits are lacking on the single specimen available. However, inflorescences of the two are quite different. Pholidostachys amazonensis has spicate inflorescences with a well-developed peduncle, absent rachis, and 1 rachilla, this arching at anthesis. Pholidostachys synanthera has inflorescences branched 1–2 orders with a well-developed peduncle and rachis, and several rachillae, these spreading at anthesis.

1. Pholidostachys amazonensis Henderson , sp. nov. (Appendix IV, Plate 1)

It differs from other species in its spicate inflorescence and proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved.

Type:— PERU. Amazonas: Bagua Province, along roadside from Chiriaco to Puente Venezuela , 43 km (by road) NE of Chiriaco, ca. 1050–2400 ft., 5 November 1978, P. Barbour 4471 (holotype USM n.v., isotype MO!) .

Stems no data. Leaves number per stem no data; sheaths and petioles no data; rachises 42.0 cm long, 3.7 mm diameter; pinnae 6 per side of rachis; basal pinna no data; apical pinna length no data, 3.5 cm wide, forming an angle of 15° with the rachis. Inflorescences spicate, with a well-developed peduncle, absent rachis, and 1 rachilla, this arching at anthesis; prophylls and peduncular bracts woody, not covering rachilla at anthesis; prophylls and peduncular bracts no data; peduncles length no data, 3.2 mm diameter; rachilla 1, 18.7 cm long, 5.9 mm diameter; proximal lips of flower pits regularly shaped, rounded, not covering pits before anthesis, recurved; fruits no data.

Distribution and habitat. At 4°56’N and 78°10’W in Peru (Amazonas) at medium elevations in lowland rainforest ( Fig. 5 ).

Taxonomic notes. For inflorescence bracts and proximal flower pit shape, Pholidostachys amazonensis shares the same character states as P. synanthera . Fruits are lacking on the single specimen available. However, inflorescences of the two are quite different. Pholidostachys amazonensis has spicate inflorescences with a well-developed peduncle, absent rachis, and 1 rachilla, this arching at anthesis. Pholidostachys synanthera has inflorescences branched 1–2 orders with a well-developed peduncle and rachis, and several rachillae, these spreading at anthesis.

Figures

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