Geonoma concinnoidea Henderson, 2011

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 50-52

12. Geonoma concinnoidea Henderson , sp. nov. (Appendix IV, Plates 6 & 7)

Geonomae concinnae crusta fructuum fibris emergentibus differt.

Type: PANAMA. Comarca de San Blas: Yar Bired (San José), between Cangandi and San José, 9°20’N 79°08’W, 400–500 m, 5 February 1986, G. de Nevers & H. Herrera 6942 (holotype NY!, isotype MO!).

Plants 2.0(1.0–3.1) m tall; stems 2.7(1.6–4.0) m tall, 0.6(0.4–1.0) cm in diameter, solitary or clustered, canelike; internodes 1.8(0.7–4.5) cm long, yellowish and smooth. Leaves 6(5–8) per stem, undivided or irregularly pinnate, not plicate, bases of blades running diagonally into the rachis; sheaths 7.5(4.5–12.0) cm long; petioles 9.4(3.0–19.0) cm long, drying green or yellowish; rachis 21.0(9.6–37.0) cm long, 2.2(1.5–3.3) mm in diameter; veins raised and rectangular in cross-section adaxially; pinnae 1(1–3) per side of rachis; basal pinna 23.1(20.0–25.6) cm long, 5.7(3.6–6.8) cm wide, forming an angle of 30(22–44)° with the rachis; apical pinna 14.7(9.0–20.5) cm long, 5.7(3.0–6.4) cm wide, forming an angle of 30(20–37)° with the rachis. Inflorescences branched 2 orders; prophylls and peduncular bracts not ribbed with elongate, unbranched fibers, flattened, deciduous; prophylls 5.5(3.0–9.1) cm long, not short and asymmetrically apiculate, the surfaces ridged with close, equal, parallel, non-dividing ridges, scarcely tomentose between the ridges, without unequally wide ridges; peduncular bracts 4.5 cm long, well-developed, inserted 0.2(0.1–0.3) cm above the prophyll; peduncles 4.4(2.0–8.4) cm long, 2.7(1.7–4.2) mm in diameter; rachillae 14(7–24), 9.4(6.0–14.0) cm long, 1.4(0.8–1.9) mm in diameter, the surfaces without spiky, fibrous projections or ridges, drying brown, with faint to pronounced, 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, hood-shaped at anthesis, sometimes splitting post-anthesis; 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 flowers not projecting and persistent after anthesis; fruits 7.3(6.4– 7.7) mm long, 5.4(4.6–5.9) mm in diameter, the bases without a prominent stipe, the apices not conical, the surfaces not splitting at maturity, with fibers emerging, bumpy from the numerous, subepidermal, tangential, short fibers present, these coming to a point at fruit apices; locular epidermis with operculum, smooth, without pores.

Taxonomic notes:— Closely related to G. concinna (which see), differing from that species in its fruit surfaces with emerging fibers.

Subspecific variation:— Two traits (stem branching, leaf division) vary within this species. There is geographic discontinuity, and specimens come from three different areas in Panama; the eastern end of the Central Cordillera; the mountain systems east of the Canal Zone; and the western end of the Serranía de San Blas, with an outlier on the Serranía de Majé. This gives three geographic subgroups, excluding the outlier.

ANOVA shows that for pair wise comparison probabilities, 10 variables (plant height, stem diameter, sheath length, number of pinnae, apical pinna length, peduncle length, peduncle width, rachilla length, rachilla width, number of rachillae) differ significantly (P <0.05) between one pair of subgroups, and one variable (rachis length) differs amongst all three groups. Based on these results, the three Panamanian subgroups are recognized as subspecies (subspp. concinnoidea , coclensis, jefensis).

Key to the subspecies of G. concinnoidea

1

- 2 - Rachis 28.5(20.0–37.0) cm long; western end of the Serranía de San Blas, with an outlier on the Serranía de Majé... ..................................................................................................................................................... subsp. concinnoidea . Rachis 17.5(9.6–27.0) cm long; all other areas ........................................................................................................... 2 Rachillae 1.0(0.8–1.2) mm in diameter; eastern end of the Central Cordillera .................................... subsp. coclensis Rachillae 1.4(1.1–1.7) mm in diameter; east of the Canal Zone (Cerro Azul, Cerro Brewster, Cerro Bruja, Cerro Jefe) ......................................................................................................................................................... subsp. jefensis