Geonoma stricta subsp. arundinacea (Martius) Henderson, 2011

Henderson, Andrew, 2011, A revision of Geonoma (Arecaceae), Phytotaxa 17, pp. 1-271 : 144-145

60c. Geonoma stricta subsp. arundinacea (Martius) Henderson , comb. & stat. nov.

Basionym: Geonoma arundinacea Martius (1823: 17) . Lectotype (selected by Wessels Boer 1968): BRAZIL. Amazonas: “Rio Negro”, no date, C. Martius s.n. (lectotype M!).

Geonoma pycnostachys Martius (1823: 16) . Type: BRAZIL. Amazonas: Rio Japurá, no date, C. Martius s.n. (holotype M!).

Geonoma stricta var. trailii (Burret) Henderson (1995: 288) . Geonoma trailii Burret (1930a: 178) . Geonoma elegans Martius var. amazonica Trail (1876: 324) . Type: BRAZIL. Amazonas: Rio Purus, Barreiras de Mancira, 29 September 1874, J. Trail 1032/CXXXIII (holotype K!).

Geonoma piscicauda Dammer (1907: 123) . Geonoma stricta var. piscicauda (Spruce) Henderson (1995: 287) . Type: BRAZIL. Acre: Rio Juruá, Juruá-mirim, May 1901, E. Ule 5520 (holotype B, destroyed, isotypes F!, K!, MG!).

Geonoma wittiana Dammer (1907: 124) . Type: BRAZIL. Acre: Rio Juruá, Juruá-mirim, September 1901, E. Ule 5884 (holotype B, destroyed, isotype MG!).

Geonoma uleana Dammer (1907: 122) . Type: BRAZIL. Acre: Rio Juruá, Cachoeira, May 1901, E. Ule 5521 (holotype B, destroyed, isotype MG!).

Geonoma trauniana Dammer (1907: 124) . Type: BRAZIL. Acre or Amazonas: Rio Juruá, Fortaleza, October 1901, E. Ule 5946 (holotype B, destroyed, isotype MG!).

Geonoma dasystachys Burret (1930a: 251) . Type: BRAZIL. Amazonas: Rio Negro, Jauapasse assu, 5 July 1874, J. Trail 981/XC (holotype K!).

Geonoma bella Burret (1935b: 304) . Type: BRAZIL. Amazonas: Mun. Tefé, Paranagua, 22 May 1933, B. Krukoff 4543 (holotype B, destroyed, isotypes F!, M!, MO!, NY!, US!).

Leaves undivided or pinnate; veins raised and rectangular in cross-section adaxially, or not raised or slightly raised and triangular in cross-section adaxially; pinnae 2(1–12) per side of rachis. Inflorescences unbranched or branched; staminate flowers deciduous or persistent after anthesis.

Distribution and habitat:— From 2°30’N– 17°50’S and 49°32’– 78°42’W in the western Amazon region of Venezuela, Colombia, Ecuador, Peru, and Brazil and eastern Andean slopes in Ecuador, at 416(75–1850) m elevation in lowland or montane rainforest ( Fig. 38 ).

This is a widespread and extremely variable subspecies which can be divided into various morphotypes, mostly based on leaf size and shape.

In the western Amazon basin of Colombia, Ecuador, Peru, and Brazil there is a morphotype ( arundinacea ) with undivided or pinnate leaves with non-raised adaxial veins and unbranched or branched inflorescences with deciduous staminate flowers. In some cases specimens approach those of the trailii morphotype and are only distinguished by their non-raised adaxial veins. For example, in Yasuni National Park in Amazonian Ecuador, there are two forms of this morphotype. One has smaller leaves and branched inflorescences, the other larger leaves and unbranched inflorescences. The latter exactly resemble trailii in their leaves, except for the non-raised veins. There are no specimens of trailii from Yasuni, but it occurs just to the west of the Park. There may be introgression between arundinacea and trailii in this area. A specimen (Vásquez 7413) from Amazonian Peru has an exceptionally long rachilla.

On eastern Andean foothills and in the western Amazon region in Colombia, Ecuador, and Peru there is a morphotype (elevata) with small, undivided leaves with narrow basal angles and raised adaxial veins and unbranched inflorescences with persistent staminate flowers. Inflorescences are usually pendulous.

In the western Amazon region in Colombia, Peru, and Brazil there is a morphotype ( minor ) with small, undivided, rarely pinnate leaves and unbranched inflorescences with deciduous staminate flowers. Veins are difficult to score in this morphotype.

In the western Amazon region in Colombia, Ecuador, Peru, and Brazil there is a morphotype ( piscicauda ) with large, undivided leaves with narrow basal angles and raised adaxial veins. Inflorescences are unbranched and often pendulous, and have persistent staminate flowers. The types of G. piscicauda and G. wittiana are of this morphotype.

On eastern Andean foothills in Ecuador at 1217(825–1600) m elevation there is a morphotype (puyo) with pinnate leaves and branched or unbranched inflorescences with deciduous staminate flowers. Veins are difficult to score in this morphotype, and there seem to be several local variants. Some specimens (Balslev 6419, Cerón 6552, 7454, Harling 3762, Øllgaard 98478) have exceptionally long inflorescences.

A widespread morphotype ( pycnostachys , Plates XX, XXI) occurs in the central and western Amazon region in Venezuela, Colombia, Ecuador, Peru, and Brazil. It has mostly undivided leaves with the veins not raised adaxially, and unbranched inflorescences with persistent staminate flowers. The type of G. pycnostachys is of this morphotype. Several specimens from the central Amazon region (Campos 519, Cid 545, Henderson 662, 1043, 1066, Nee 42341, 42897) are more similar to subsp. stricta in their small leaves than they are to other, more westerly specimens of pycnostachys . However, small-leaved pycnostachys also occur sporadically in the western Amazon region. Specimens (Díaz 7327, Kajekai 300, Rodríguez 261, 568, Rojas 592, Vásquez 18741, 20286, 24195, 24322) from southeastern Ecuador and northwestern Peru (Amazonas) have exceptionally large leaves, thick rachillae, and large fruits. Specimens from eastern Andean slopes in Ecuador have pinnate leaves with few divisions. Some specimens (e.g., Lewis 10332, Vásquez 14439, and probably several others) appear to be hybrids between this and the trailii morphotype, and others appear to be hybrids between this and the piscicauda morphotype.

In the central and western Amazon region of Colombia, Ecuador, Peru, Bolivia, and Brazil, with outliers in the central Amazon of Brazil and in Bolivia, there is a morphotype ( trailii ) with pinnate leaves with raised adaxial veins and unbranched inflorescences with deciduous staminate flowers. The types of Geonoma elegans var. amazonica , Geonoma trauniana , Geonoma dasystachys , and Geonoma bella are of this morphotype. The two outlying specimens in Bolivia occur in the same area as outlying specimens of the tapajotensis morphotype of G. macrostachys . As in the pycnostachys morphotype, specimens from southeastern Ecuador and northwestern Peru (Amazonas) have exceptionally large inflorescences.

In the southwestern Amazon region in Peru and Brazil there is a morphotype ( uleana ) with undivided or pinnate leaves with non-raised adaxial veins and unbranched inflorescences with deciduous staminate flowers. It has longer peduncular bracts—3.5 (2.7–4.7) versus 0.5(0.1–4.0) cm—than other morphotypes. The type of G. uleana is of this morphotype.

Figures

FIGURE 38. Distribution maps of Geonoma spinescens, G. stricta subsp. stricta, G. stricta subsp. antioquiensis, and G. stricta subsp. arundinacea.