Olmeca Soderstr., 1982

Ruiz-Sanchez, Eduardo, Clark, Lynn G., Londoño, Ximena, Mejía-Saulés, Teresa & Rodríguez, Gilberto Cortés, 2015, Morphological keys to the genera and species of bamboos (Poaceae: Bambusoideae) of Mexico, Phytotaxa 236 (1), pp. 1-24 : 17-18

Olmeca Soderstr.

Rhizomes pachymorph with culm necks short to elongated; culms hollow, erect, scandent and clambering, culm leaf sheaths well developed, auricles present or absent, fimbriae present, oral setae present, culm leaf blades erect or reflexed, deciduous; branching intravaginal; nodes with one primary bud, developing into 1 branch per node; synflorescences paniculate; spikelets linear-lanceolate; glumes 2, glabrous, awned or awnless; 2–12 florets; lemmas awned or mucronate, glabrous or hispid at the apex; lodicules 3, stamens 3; stigmas 2–3; fruit a basic or bacoid (fleshy) caryopsis. ( Fig. 6A–F ).

1. Rhizome necks 300–900 cm long; fruit a bacoid caryopsis; in tropical rain forests at low elevations from 0– 900 m ......................2

1. Rhizome necks 4–30 cm long; fruit a basic caryopsis; in cloud forests at middle elevations, from 1500–2400 m ...........................3

2. Culms erect to apically arched, culm diameter 4.5–5 cm ; culm leaf blades erect; rhizome necks up to 3 m long........ Olmeca recta Endemic to Mexico ; Chiapas, Veracruz; 0– 900 m.

2. Culms scandent, culm diameter ca. 2 cm ; culm leaf blades reflexed; rhizome necks to 9 m long ..................................... Ol. reflexa Endemic to Mexico ; Chiapas, Oaxaca, Veracruz; 100– 900 m.

3. Culms erect and arched for the upper third; culm diameter 1–2 cm; foliage leaf blades adaxially green ........................ Ol. clarkiae Mexico and Honduras; Chiapas; 1600–1900 m.

3. Culms scandent and decumbent; culm diameter 0.5–1.0 cm; foliage leaf blades adaxially glaucous...............................................4

4. Culms 5–6 m long ; foliage leaves 4–6 per complement, the blades 18.5–26.5 cm long and 0.7–1.0 cm wide; foliage leaf oral setae 5–10 mm long and 0.2 mm wide.......................................................................................................................................... Ol. fulgor Endemic to Mexico; Oaxaca, Veracruz; 1600–2400 m .

4. Culms 6.5–8.0 m long ; foliage leaves 9–13 per complement, the blades 20–30 cm long and 1.5–2.5 cm wide; foliage leaf oral setae 12–22 mm long and 0.5–1.0 mm wide...................................................................................................................... Ol. zapotecorum Endemic to Mexico; Oaxaca ( Cerro Chayotepec ); 1470–1500 m .

Figures

FIGURE 6. A. Olmeca recta, showing culm leaf sheath and erect blade. B. Olmeca reflexa, showing spikelets and fruits. C. Olmeca reflexa, liguar area of the culm leaf, showing fimbriae, oral setae and the reflexed blade. D. Olmeca zapotecorum, showing foliage complements. E. Olmeca fulgor, showing foliage complements. F. Olmeca clarkiae, showing branches and foliage leaves. Photos by E. Ruiz-Sanchez.