Geonoma paradoxa Burret, Notizbl. Bot. Gart. Berlin-Dahlem 11: 1040 (1934)

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Distribution

Map uses TDWG level 3 distributions (http://www.nhm.ac.uk/hosted_sites/tdwg/geogrphy.html)
Colombiapresent (World Checklist of Arecaceae)B
Ecuadorpresent (World Checklist of Arecaceae)B
From 1°15-3°59'N and 76°58'-8°40'W on the Pacific coast of Colombia and Ecuador at 118(10-400) m elevation in lowland rainforest (Henderson, A.J. (2011) A revision of Geonoma. Phytotaxa 17: 1-271.)A

Discussion

  • Taxonomic notes: - Geonoma paradoxa is a member of the G. macrostachys clade, within which it is related to a group of species which includes G. macrostachys, G. multisecta, G. poiteauana, and G. schizocarpa. It differs from these in its distal lips which are scarcely raised rims. Despite having a relatively narrow distribution it is confusingly variable, as explained below.

    Subspecific variation: - One trait (leaf division) varies within this species. All specimens but two have undivided leaves. The specimens are clearly divisible into small and large size subgroups. Although there are only six large size specimens and these have missing data, of the eight variables with enough data, large size specimens differ from small size ones in seven variables (rachis length, rachis width, basal pinna angle, apical pinna angle, peduncle width, rachilla length, rachilla width)(t-test, P <0.05). All large size specimens are from low elevations (10-60 m) near the sea in the Río Naya-Río Yurumangui region of Valle. Small size specimens occur at higher elevations (25-400 m) from near Buenaventura in Valle to northwestern Ecuador. There is variation in connectives. Of the nine (of 16) specimens with staminate flowers, three small size specimens from the northern most part of the range have well-developed connectives. Two, from the most southern part of the range, have poorly developed connectives, and one, from the central part of the range has aberrant flowers in which one theca of a pair is developed and the other not. The large size specimens also appear to have aberrant flowers. Without more specimens it is not possible to understand the variation within this species, and no subspecies are recognized. (Henderson, A.J. (2011) A revision of Geonoma. Phytotaxa 17: 1-271.)A

Description

  • Plants 0.8(0.7-1.0) m tall; stems 0.2(0.1-0.3) cm tall, 1.3(1.2-1.3) cm in diameter, solitary, not cane-like; internodes 0.4(0.3-0.4) cm long, not scaly. Leaves 9(6-12) per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 8.0(3.5-13.0) cm long; petioles 38.5(19.0-63.0) cm long, drying green or yellowish; rachis 36.7(21.5-63.0) cm long, 3.5(1.9-6.4) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 1(1-3) per side of rachis; basal pinna 37.5 cm long, 11.0 cm wide, forming an angle of 28(19-40)° with the rachis; apical pinna 13.5(11.5-17.2) cm long, 11.0 cm wide, forming an angle of 39(29-50)° with the rachis. Inflorescences unbranched; prophylls and peduncular bracts ribbed with elongate, unbranched fibers, both bracts tubular, narrow, elongate, closely sheathing the peduncle, more or less persistent; prophylls 14.8(13.6-15.7) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 8.8(5.5-12.0) cm long, well-developed, inserted 1.5(0.7-2.2) cm above the prophyll; peduncles 58.8(27.5-100.0) cm long, 2.0(1.3-3.7) mm in diameter; rachillae 1, 11.3(7.8-16.0) cm long, 3.6(2.7-4.6) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown or yellow-brown, without short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits spirally arranged, glabrous internally; proximal lips with a central notch before anthesis, often the two sides of the notch overlapping, not recurved after anthesis, not hood-shaped; proximal and distal lips drying the same color as the rachillae, not joined to form a raised cupule, the proximal lip margins overlapping the distal lip margins; distal lips a scarcely raised rim; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging or not diverging at anthesis, inserted onto poorly to well-developed, non-split, jointed connectives, connectives when well-developed alternately long and short; anthers short at anthesis, remaining straight and parallel; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes lobed at the apex, the lobes spreading at anthesis, acuminate, those of non-fertilized pistillate flowers not projecting and persistent after anthesis; fruits 9.4(8.9-9.7) mm long, 5.6(5.3-6.0) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, not bumpy, not apiculate; locular epidermis with operculum, smooth, without pores. (Henderson, A.J. (2011) A revision of Geonoma. Phytotaxa 17: 1-271.)A