Geonoma undata subsp. undata

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 156-158

67a. Geonoma undata subsp. undata

Geonoma densa Linden & Wendland (1856: 333) . Type: COLOMBIA. Santander: Cachiri, no date, N. Funck & L. Schlim s.n. (holotype BR n.v., isotype K!), synon. nov.

Geonoma margaritoides Engel (1865: 682) . Type: VENEZUELA. Táchira: La Grita, no date, F. Engel s.n. (holotype B, destroyed, isotype LE!).

Geonoma barthia Engel (1865: 688) . Type: VENEZUELA. Mérida: no locality, no date, F. Engel s.n. (holotype B destroyed, isotype LE!).

Geonoma iodolepis Burret (1930a: 198) . Type: COLOMBIA. Antioquia: Amalfi, 1800–2000 m, 14 May 1880, W. Kalbreyer 1668 (holotype B, destroyed). Neotype (designated by Bernal et al. 1989): COLOMBIA. Valle del Cauca: La Cumbre, Western Cordillera, 1700–2100 m, 9 September 1922, E. Killip & T. Hanzen 11137 (neotype NY!, isoneotype US!).

Geonoma weberbaueri Dammer ex Burret (1930a: 221) . Type: PERU. Huánuco: SW of Manzón, no date, A. Weberbauer 3552 (holotype B n.v., holotype image!), synon. nov.

Geonoma megalospatha Burret (1930a: 218) . Type: PERU. Huánuco: Río Pozuzo, 1909–1914, A. Weberbauer 6800 (holotype B n.v., holotype image!, isotypes F!, GH!).

Leaves veins raised and rectangular in cross-section adaxially; basal pinna 3.0(0.5–14.0) cm wide; apical pinna 10.6(2.0–30.0) cm wide. Inflorescences prophyll margins with irregular, spine-like projections; flower pits usually spirally arranged, not distantly spaced.

Distribution and habitat:— From 10°56’N– 17°48’S and 63°28’– 80°42’W in Andean regions of South America from Venezuela to Bolivia at 1964(550–3370) m elevation in lowland or, more often, montane rainforest ( Fig. 42 ).

There is considerable variation in this widespread subspecies and there are many local morphotypes. These are difficult to distinguish from one another and are variable within themselves.

In Venezuela, Colombia, Ecuador, Peru, and Bolivia there is a widespread morphotype ( margaritoides morphotype). It has 25.4(6.4–54.0) cm long and 4.3(2.2–7.1) mm wide rachillae and 8.5(5.5–12.5) mm long and 6.3(4.2–8.9) mm wide fruits. This morphotype is relatively uniform throughout the northern part of its range, usually with elongate rachillae, often tricussately arranged flower pits, and small fruits (e.g., types of G. margaritoides and G. barthia ). However, there are many exceptions, notably specimens with unusually short and thin, or unusually short and thick rachillae that occur in scattered localities.

There is geographical variation in this morphotype. Linear regression shows there are significant associations between elevation and one plant, two leaf, and five inflorescence variables. Squared multiple R for the regression of plant height on elevation is 0.07, basal pinna angle 0.19, apical pinna angle 0.11, prophyll length 0.35, interbract distance 0.22, number of rachillae 0.76, rachilla width 0.05, and fruit diameter 0.19. With increasing elevation, pinnae have narrower angles. prophylls and interbract distances are longer, rachillae wider, and fruits larger.

Some specimens from the Coastal Range in Venezuela ( undata morphotype) occur at higher elevations and have greater interbract distances, longer peduncles, shorter rachillae, and longer and wider fruits. The type of G. undata has this kind of inflorescence.

Some specimens from Venezuela (Andes and Peninsula Paraguaná, Falcón) and Colombia are distinctive in their shorter, thinner rachillae ( densa morphotype). The type of G. densa has this kind of rachillae.

Some specimens lack distal lips of the flower pits ( megalospatha morphotype). These are hypothesized to be hybrids between the margaritoides morphotype and Geonoma trigona . They share with G. trigona the absence of an upper lip, and occur in two areas where G. trigona occurs ( Ecuador, Peru). It is predicted that G. trigona will be found in Bolivia at the third hybrid locality. The type of G. megalospatha has this kind of flower pits.

Specimens from the Western Cordillera of the Colombian Andes ( iodolepis morphotype) have small leaves like those of G. orbignyana and inflorescences with short, thin rachillae 9.0(7.0–11.0) cm long and 2.6(2.1–3.5) mm wide. Fruits are 8.5 mm long and 6.3 mm wide. The type of G. iodolepis is of this morphotype.

In the Venezuelan, Colombian, Ecuadorian, and Peruvian Andes, and also the Sierra Nevada de Santa Marta in Colombia, there is an extremely variable morphotype ( weberbaueri morphotype). Specimens have plicate leaves, short, thick rachillae 19.0(9.0–33.0) cm long and 5.7(3.0–9.4) mm wide, and 12.5(8.0–15.4) mm long and 8.7(5.0–12.0) mm wide fruits. Most specimens with fruits have large-sized fruits, but a few specimens (Dodson 15213, Vásquez 26597) have small, globose fruits. This morphotype differs from the margaritoides morphotype in 10 variables. See under Geonoma orbignyana subsp. orbignyana for potential hybrids with that subspecies.

There is geographical variation in this morphotype. Linear regression shows there are significant associations between elevation and three inflorescence variables. Squared multiple R for the regression of prophyll length 0.39, interbract distance 0.26, and peduncle length 0.33. Prophylls, interbract distances, and peduncles increase in length with increasing elevation.

On eastern Andean slopes in Ecuador, particularly from Mera and Puyo, specimens (mera-puyo morphotype) have relatively slender inflorescences, 14.9(9.8–21.0) cm long and 2.1(1.5–2.5) mm wide rachillae, and 6.0(5.9–6.0) mm long and 4.6(4.1–5.0) mm wide fruits.

Also on eastern Andean slopes in Ecuador, there are specimens (intermediate morphotype) which appear intermediate between the margaritoides morphotype and Geonoma orbignyana . They have small leaves and inflorescences, like the latter, but the bracts of the inflorescence are like those of the former. They have 16.8(8.8–29.3) cm long and 3.8(3.1–5.0) mm wide rachillae and 8.2(7.6–8.8) mm long and 6.1(5.8–6.3) mm wide fruits.

One specimen (sira morphotype) from Peru (Huánuco) has small leaves like those of Geonoma orbignyana , slender rachillae 13.5 cm long and 1.9 mm wide, almost decussately arranged flower pits, and 8.9 mm long and 6.3 mm wide fruits.

Figures

FIGURE 42. Distribution maps of Geonoma undata subsp. undata, G. undata subsp. appunniana, G. undata subsp. dussiana, and G. undata subsp. edulis.