Prodr. Fl. Norf. 35 (1833), in obs. (Phenakosperum); Miq. in Bot. -Zeitung, iii.345 (1845), descr. ampl.
Type: P. guyannense (L.C. Rich.) Endl. ex Miq.
Large, rhizomatous, arborescent herbs forming clones with erect, leafy shoots from 3.2-10.3 m in height (at reproductive maturity). Pseudostem palm-like, 3-7.4 m tall, 11-17 cm in diameter, composed of a central fibrous stem covered with overlapping sheathing leaf bases. Leaves large, distichous with all blades lying in a single plane, deciduous, up to 12 persisting at the time of flowering; petiole green, slightly glaucous, 0.37-1.92 cm long, 2.0-3.2 cm in diameter; blade with central midrib and lateral venation, base usually cordate, apex obtuse, the upper surface green, the lower surface green, glaucous, 1.0-2.7 m long, 47-85 cm wide. Inflorescence terminal on leafy shoot, erect, held conspicuously above the leaves, consisting of a peduncle, rachis, and bracts, to 3.65 m in height; peduncle green, glaucous, 1.2-2.0 m long, 7-18 cm in diameter; rachis 2.5-9.0 cm in diameter, internodes 6-24 cm long; bracts distichous, 3-10 per inflorescence, oriented 90 degrees to axis of inflorescence, green to yellow green with a waxy coating, 23-44 cm long, 18-34 cm wide at base, each subtending a cincinnus of up to 25 flowers. Each flower is subtended by an opaque, cream-colored, acuminate, persistent floral bract which becomes papery at fruit maturity, 17-34 cm long, 5.8-8.5 cm wide at base; floral bracts and immature flowers covered with mucilaginous secretions. Flowers hermaphroditic; pedicel 1-1.2 cm long, cream-colored; perianth to 28 cm in length, consisting of two whorls united at the base into a prolonged, solid tube above the ovary, tube bicarinate, white, 9 cm long, 1.8 cm wide; the calyx with one free abaxial sepal, 17 cm long, 3.5 cm wide, and two free, slightly imbricate, adaxial sepals, 18 cm long, 3.5 cm wide, creamy white; the corolla with two connate abaxial petals, overlapping but free at base, fused from middle to apex, margins becoming revolute, 14 cm long, 2.5 cm wide, and one free adaxial petal, 12 cm long, 3.0 cm wide, creamy white with thin dark green margins; stamens five, abaxial stamen of inner whorl absent, the filaments long, linear, geniculate, attached basally to apex of perianth tube and distally to apex of fused sepals, 8.5 cm long, the anthers 4-loculate, linear, 7 cm long, dehiscence longitudinal; pollen in monads, very large (ca. 110 mm in diameter), spheroidal to ovoid with polar protruberances, inaperturate, sculpturing psilate, wall with thin exine and elaborate 3-4-layered intine; ovary inferior, 3.5 cm long, 2 cm wide, bicarinate, white, three-celled, placentation axial, the ovules numerous in 4 rows per locule, the style filiform, straight, lax, the stigma conical, 1.5 cm long. Fruits loculicidal, woody capsules, 15 cm long, 8 cm wide; seeds arillate, aril composed of bright red orange threads, 8-10 mm long, 6-8 mm wide, up to 400 seeds per fruit; embryo straight; endosperm copious. 2n = 22 (From Manning & Goldblatt, 1989)
Phenakospermum is widely distributed throughout the Amazonian Basin in tropical northern and central South America east of the Andes.
Most taxonomists (Lane 1955; Tomlinson 1960; Andersson 1985; Maas 1985; Kress 1990) recognize only a single species, P. guyannense (L.C. Rich.) Endl. ex Miq., in the genus. A second species, P. amazonicum (Mart.) Miq., at one time was segregated into a separate genus Musidendron Nikai, but is now considered to be conspecific with P. guyannense.
Ecology and Pollination Biology:
This genus is particularly abundant in transitional habitats between tall wet forests and open areas of savanna and cerrado. Flowering occurs from the end of the rainy season to the middle of the dry season and a single inflorescence can produce flowers for two to four months. The large, hermaphroditic flowers emerge from the protective inflorescence bracts just before sunset and are receptive for one night. From 1.2 to 3.0 ml of hexose-dominant nectar, with a mean concentration of 16.9%, is produced by each flower. Flower-visiting bats in the genus Phyllostomus were observed to be the primary pollinators in French Guiana. Caluromys philander, a nocturnally foraging marsupial, visited the flowers to rob nectar, but did not effect pollination. (Kress and Stone, 1993). Seed dispersal is probably by birds which are attracted to the bright red orange arils exposed in the open capsules.
Common Names, Uses and Notes:
Traveler's Palm (more often applied to Ravenala); paloeloe, haritsi (Surinam); sororoca (Brazil). Leaves are used for thatching roofs (Maas, 1985) and temporary umbrellas.
Phenakospermum is most closely related to Strelitzia of South Africa. Although it resembles the commonly cultivated Ravenala in its conspicuous distichous leaf arrangement, it is only occasionally grown as an ornamental.
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