Geonoma brongniartii Martius 1843
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma brongniartii

description: 6. Geonoma brongniartii Martius (1843: 24). Type: BOLIVIA. Cochabamba: Prov. Carrasco, no date, A. d’Orbigny 39 (holotype P n.v., isotype F!).
Plants 1.5(0.5–3.0) m tall; stems 0.4(0.1–1.0) m tall, 1.7(0.9–3.0) cm in diameter, solitary or clustered, not cane-like; internodes 0.5(0.3–0.8) cm long, not scaly. Leaves 8(4–12) per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 13.6(5.0–22.0) cm long; petioles 48.3(14.0–90.0) cm long, drying green or yellowish; rachis 53.4(20.0–80.0) cm long, 3.7(1.9–6.2) mm in diameter; veins raised and rectangular in cross-section adaxially or not raised or slightly raised and triangular in cross-section adaxially; pinnae 5(1–19) per side of rachis; basal pinna 30.0(16.0–54.0) cm long, 4.7(0.3–28.5) cm wide, forming an angle of 48(7–97)° with the rachis; apical pinna 21.1(4.5–35.0) cm long, 11.5(2.0–37.5) cm wide, forming an angle of 32(20–52)° with the rachis. Inflorescences unbranched or branched 1 order; prophylls and peduncular bracts ribbed with elongate, unbranched fibers, both bracts tubular, narrow, elongate, closely sheathing the peduncle, more or less persistent; prophylls 19.6(5.7–35.5) cm long, not short and asymmetrically apiculate, the surfaces not ridged, without unequally wide ridges; peduncular bracts 19.4(12.6–31.5) cm long, well-developed, inserted 5.7(0.5–18.5) cm above the prophyll; peduncles 34.6(18.0–64.0) cm long, 2.9(1.5–6.5) mm in diameter; rachillae 1(1–6), 24.4(8.6–46.0) cm long, 3.7(1.7–7.3) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown or yellow-brown, the surfaces without short, transverse ridges, not filiform and not narrowed between the flower pits; flower pits usually spirally arranged, sometimes tricussately, then the groups not closely spaced nor consistently arranged throughout the rachillae, glabrous internally (sometimes some hairs along the proximal and distal lip margins); 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 a scarcely raised rim; 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 flowers not projecting and persistent after anthesis; fruits 6.8(5.3–8.3) mm long, 5.7(4.5–6.5) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, without fibers emerging, bumpy from the numerous, subepidermal, tangential, short fibers present, these coming to a point at fruit apices; locular epidermis without operculum, smooth or sculpted and then usually also with a raised, meridional ridge, without pores.
Taxonomic notes:— The holotype of Geonoma brongniartii at P has not been seen. A specimen from F, labeled “ Geonoma elegans Mart., Bolivia, Yapacani, 400 m, Otto Kuntze VI 92 ”, has written on it, apparently in Wessels Boer’s handwriting, “leg. d’Orbigny 39, Type of G. brongniartii ”. This specimen, clearly not representing G. elegans, is referred to by Wessels Boer (1968) as being an isotype of G. brongniartii. Although it is not clear why Wessels Boer thought the specimen was an isotype, it is treated as such here.
Subspecific variation:— Five traits (stem branching, leaf division, adaxial veins, inflorescence branching, locular epidermis sculpting) vary within this species. There is evidence of geographic discontinuity, but some of the gaps in the distribution may be a result of insufficient collecting. Leaving aside stem branching, leaf division, and locular epidermis sculpting (for which there are few data), there is no correspondence between geography and variation in adaxial veins or inflorescence branching, except for one subgroup of specimens from sub-Andean Peru. These have raised adaxial veins and mostly branched inflorescences. These specimens differ significantly from all other specimens in eight variables (plant height, number of pinnae, basal pinna width, apical pinna width, rachillae length, rachillae width, fruit length, and fruit diameter)(t -test, P <0.05). Based on this, they are recognized as a separate subspecies (subsp. pascoensis). All other specimens are included in subsp. brongniartii.
Key to the subspecies of G. brongniartii
1 Inflorescences unbranched; fruits 6.9(5.3–8.3) mm long; widespread ............................................ subsp. brongniartii
- Inflorescences unbranched or usually branched 1 order; fruits 5.9(5.7–6.1) mm long; Peru (Junín, Pasco) ................. ............................................................................................................................................................ subsp. pascoensis
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 42-43, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362