Bactris gracilior Burret, Repert. Spec. Nov. Regni Veg. 34: 216 (1934)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Costa Ricapresent (World Checklist of Arecaceae)B
Nicaraguapresent (World Checklist of Arecaceae)B
Panamápresent (World Checklist of Arecaceae)B
Atlantic slope from southern Nicaragua (Zelaya), Costa Rica (Alajuela, Cartago, Heredia, Limón), and Panama (Bocas del Toro, Coclé, Colon, Darién, Panamá, San Bias).
Lowland rain forest at 60-1000 m elevation. (Henderson, A.J., Bactris (Palmae) in Flora Neotropica Monographs 79. 2000)A

Discussion

  • Bactris gracilior is diagnosed by its narrowly elliptical, gradually aristate pinnae (characteristically shiny when dry), and obovoid, bluntly rostrate, orange fruits that are 1-1.5 x 0.9-1.1 cm.
    This is the species referred to as "Bactris sp. nov. fide Moore" by Chazdon (1985, 1987). Some specimens from Costa Rica and Nicaragua have black, 2-11 mm spines on the veins abaxially (Moore 6629, Robles 1668, Stevens 5083). One specimen, not included in the above description but possibly belonging here, has 29-33, linear pinnae per side (Panama. Bocas del Toro: E of Gualaca-Chiriquí Grande rd., 10 mi N of continental divide, 8°55'N, 82°5'W, 19 Jan 1989, de Nevers et al. 8833 (CAS)). (Henderson, A.J., Bactris (Palmae) in Flora Neotropica Monographs 79. 2000)A

Description

  • Stems cespitose, 2-4(-5) m tall, ca. 2 cm diam., spiny on internodes.
    Leaves 5-9; leaf spines scattered, black, terete, to 2(-5) cm long, on lateral surfaces of sheath, usually absent from petiole and rachis, rarely on rachis; sheath to 28 cm long; ocrea to 10 cm long; petiole 0.2-1.1 m long; rachis 42-96 cm long; pinnae 10-24 per side, irregularly arranged in clusters on alternating sides of the rachis proximally, more regularly arranged distally, spreading in different planes, narrowly elliptical, gradually aristate, glabrous, dull green adaxially, brownish and shiny abaxially on drying, sometimes with minute, forward pointing marginal spines; middle pinnae 18-39(-45) x 2.5-4.4 cm.
    Inflorescences interfoliar; peduncle 6-10 cm long, recurved, not spiny or sparsely spiny; prophyll 8-12 cm long, thin, chartaceous; peduncular bract 15-24 cm long, sparsely covered with short, black or brown spines, occasiOnally almost glabrous; rachis 3-3.6 cm long; rachillae 8-23, 7-10 cm long, at anthesis densely covered with moniliform trichomes; triads irregularly arranged among paired or solitary staminate flowers; staminate flowers 3-4 mm long; sepal lobes ca. 1 mm long; petals 3-4 mm long; stamens 6; pistillode absent; pistillate flowers to 3 mm long; calyx cupular, to 1 mm long; corolla tubular, to 3 mm long; staminodes 6, minute, or absent ;fruits 1-1.5 x 0.9-1.1 cm,obovoid, bluntly rostrate, orange; mesocarp mealy; endocarp turbinate, pitted apically, the pores equidistant or displaced longitudinally; endocarp fibers few; fruiting perianth with minute calyx and truncate corolla, without staminodial ring. (Henderson, A.J., Bactris (Palmae) in Flora Neotropica Monographs 79. 2000)A