Geonoma ferruginea Wendland ex Spruce 1871
Creators: name: Henderson, Andrew
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Plantae
Tracheophyta
Liliopsida
Arecales
Arecaceae
Geonoma
Geonoma ferruginea

description: 22. Geonoma ferruginea Wendland ex Spruce (1871: 110). Type: COSTA RICA. Heredia: Sarapiquí valley, 1857, H. Wendland s.n. (holotype K!).
Plants 2.4(1.0–4.0) m tall; stems 2.2(1.0–5.0) m tall, 1.0(0.5–1.6) cm in diameter, solitary or clustered, canelike; internodes 2.7(0.8–6.2) cm long, yellowish and smooth. Leaves 9 per stem, irregularly pinnate, not plicate, bases of the blades running diagonally into the rachis; sheaths 12.3(7.3–17.3) cm long; petioles 16.5(6.0–45.0) cm long, drying green or yellowish; rachis 30.7(16.5–53.0) cm long, 2.7(1.4–4.7) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 4(3–15) per side of rachis; basal pinna 19.2(11.7–28.0) cm long, 2.6(0.5–8.0) cm wide, forming an angle of 65(35–95)° with the rachis; apical pinna 14.8(8.6–23.0) cm long, 9.3(1.4–16.5) cm wide, forming an angle of 36(20–45)° with the rachis. Inflorescences branched 1–3 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous; prophylls 7.5(4.7–12.2) cm long, short, asymmetrically apiculate, the margins curved around the stem, the surfaces flat with dense, felty, brown tomentum, prophyll equal to and early deciduous with the peduncular bract, the surfaces not ridged, without unequally wide ridges; peduncular bracts 7.3(5.3–11.5) cm long, well-developed, inserted 0.3(0.1–0.5) cm above the prophyll; peduncles 6.4(3.7–10.7) cm long, 3.7(1.9–6.8) mm in diameter; rachillae 15(5–38), 8.2(3.8–15.0) cm long, 2.5(1.5–4.0) 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 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 onto bifid and well-developed, non-jointed connectives; 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 6.9(5.2–9.3) mm long, 5.4(4.2–7.3) 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, without pores.
Taxonomic notes:— Henderson et al. (1995) suggested that this species was part of G. longivaginata. It is closely related to that species, differing in its shorter rachillae— 8.1(3.8–15.0) cm long versus 22.9(10.0– 42.0) cm long — without short, transverse ridges.
Subspecific variation:— One trait (stem branching) varies within this species. The species has a disjunct distribution, and occurs in two areas — Nicaragua and Costa Rica, with outlying specimens in Honduras and Guatemala. Within Costa Rica, there is an isolated, lower elevation subgroup from the Sarapiquí valley. Apart from the outliers, there are three subgroups based on geography.
ANOVA shows that for pair wise comparison probabilities, 13 variables (stem diameter, rachis length, rachis width, pinnae number, basal pinna width, basal pinna angle, apical pinna width, interbract distance, peduncle length, peduncle width, rachilla width, number of rachillae, fruit diameter) differ significantly (P <0.05) between one pair of subgroups, and one (rachilla length) differs amongst all three groups. Based on these results, these three subgroups are recognized as subspecies (subspp. ferruginea, microspadix, nicaraguensis). There are only three specimens from Honduras and Guatemala—too few for analysis–—and these outliers are unplaced for subspecies.
Key to the subspecies of G. ferruginea
1 Nicaragua ...................................................................................................................................... subsp. nicaraguensis
- Costa Rica ..................................................................................................................................................................... 2
2 Rachillae 10(5–25), 9.7(6.4–15.0) cm long; Cordilleras Tilarán, Central, Talamanca, and Guanacaste ....................... ............................................................................................................................................................ subsp. ferruginea
- Rachillae 22(11–38), 5.5(3.8–8.0) cm long; Sarapiquí Valley ....................................................... subsp. microspadix
description: Published as part of Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), pp. 1-271 in Phytotaxa 17 on pages 73-74, DOI: 10.11646/phytotaxa.17.1, http://zenodo.org/record/3538362