Geonoma pauciflora Martius 1823
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma pauciflora

description: 47. Geonoma pauciflora Martius (1823: 12). Type: BRAZIL. State unknown: “in sylvis ad fluv. Amazonum”, no date, C. Martius s.n. (holotype M!). Geonoma conduruensis Lorenzi (2010: 226). Type: BRAZIL. Bahia: Itacaré, Fazenda São Miguel, km 43 rodovia Ilhéus-
Itacaré, 14˚23’S, 39˚03’W, 70 m, 24 June 2008, H. Lorenzi, L. Noblick, & A. Guimarães 6498 (holotype HPL n.v.,
isotypes CEPEC n.v., ESA n.v., NY n.v., RB n.v., SP n.v.), s ynon. nov.
Plants 1.9(1.0–3.0) m tall; stems 2.3(1.5–3.0) m tall, 0.7(0.5–1.2) cm in diameter, solitary or clustered, canelike; internodes 2.0(0.9–2.9) cm long, yellowish and smooth. Leaves 12(7–19) per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 8.4(3.7–15.5) cm long; petioles 12.8(4.5–27.0) cm long, drying green or yellowish; rachis 24.2(13.0–44.0) cm long, 2.5(1.2– 4.5) mm in diameter; veins not raised or slightly raised and triangular in cross-section adaxially; pinnae 2(1– 6) per side of rachis; basal pinna 17.5(10.5–26.0) cm long, 3.0(1.4–6.0) cm wide, forming an angle of 36(14– 66)° with the rachis; apical pinna 11.8(7.0–18.5) cm long, 8.3(5.0–18.0) cm wide, forming an angle of 30(17– 45)° with the rachis. Inflorescences unbranched or branched 1 order; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened (if tubular, narrow, and elongate then not ribbed), deciduous or persistent; prophylls 13.5(7.0–19.0) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 12.4(5.4–18.5) cm long, well-developed, inserted 3.1(1.6–5.1) cm above the prophyll; peduncles 20.8(10.5–33.5) cm long, 2.7(1.2–5.0) mm in diameter; rachillae 3(1–6), 10.7(4.7–18.2) cm long, 2.9(1.6–4.3) 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 usually spirally arranged, sometimes decussately or tricussately, then the groups not closely spaced nor consistently arranged throughout the rachillae, glabrous internally; proximal lips without a central notch before anthesis, 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 well-developed; staminate and pistillate petals not emergent, not valvate throughout; staminate flowers deciduous after anthesis; stamens 6; thecae diverging at anthesis, inserted almost directly onto the filament apices, the connectives bifid but scarcely developed; anthers short and curled over at anthesis; non-fertilized pistillate flowers deciduous after anthesis; staminodial tubes crenulate or shallowly lobed at the apex, those of non-fertilized pistillate flowers not projecting and persistent after anthesis; fruits 9.6(7.3–12.1) mm long, 7.4(5.6–8.5) mm in diameter, the bases with a prominent, asymmetric stipe, the apices conical with rounded apices, the surfaces not splitting at maturity, without fibers emerging, not bumpy, not apiculate; locular epidermis without operculum, sculpted, usually also with a raised, meridional ridge; locular epidermis without pores.
Distribution and habitat:— From 8°24’– 17°04’S and 35°04’– 41°23’W in the Atlantic Coastal Forest of Brazil from Pernambuco to Bahia, with an inland outlier in Bahia, at 291(20–770) m elevation in lowland rainforest (Fig. 30).
Taxonomic notes:— The type locality is unknown. The label of the type specimen (“in sylvis ad fluv. Amazonum”) differs from the description (“in....Provinciarum Piauhiensis et Maraguaniensis”). Geonoma pauciflora is a member of a group of species from the Atlantic Coastal Forest and adjacent Cerrado of Brazil (the G. schottiana clade, also including G. elegans, G. pohliana, and G. schottiana). Although the group is well-supported, all constituent species are extremely variable internally. Geonoma pauciflora differs from G. elegans in its flattened prophylls and peduncular bracts which are not ribbed with elongate, unbranched fibers; from G. pohliana in its prophyll surfaces not ridged and without unequally wide ridges; and from G. schottiana in its undivided or irregularly pinnate leaves.
Subspecific variation:— Three traits vary within this species (stem branching, leaf division, inflorescence branching). There is little geographic discontinuity, and the specimens are widely distributed in the northern part of the Atlantic Coastal Forest of Brazil. Leaving aside stem branching and leaf division, the remaining trait—inflorescence branching—does not divide the specimens into consistent groups. However, Geonoma pauciflora is variable in leaf division and inflorescence branching, and three morphotypes may be recognized.
The first morphotype has pinnate (rarely undivided) leaves and branched (rarely unbranched) inflorescences (pinnate-branched morphotype). This morphotype occurs in two separate areas; Pernambuco and Alagoas, and central and southern Bahia. The gap between these two areas is likely to be based on unsuitable habitat (W. Thomas, pers. comm.). However, there are too few specimens from Pernambuco and Alagoas to test for differences between the areas. Specimens of this morphotype from the most southerly part of the range in Bahia (e.g., Gentry 49920, Thomas 12020) tend to have smaller leaves and inflorescences, and may be hybrids between Geonoma pauciflora and G. elegans (which see).
The second morphotype has undivided leaves and branched inflorescences, and occurs in central Bahia with an outlier further inland (undivided-branched morphotype). The type of Geonoma conduruensis is of this morphotype.
The third morphotype has undivided leaves and unbranched (rarely branched) inflorescences, and occurs in two localities in central Bahia (undivided-unbranched morphotype).
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 114-116, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362