Bambusa, Schreber, 1789

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 : 11-12

Key to the woody genera present in Mexico (including the introduced Bambusa and Phyllostachys )

1. Culms solid (except in C. matlatzinca and C. perotensis ); nodes with one central bud subtended or flanked by few to numerous subsidiary buds/branches; branching extravaginal, intravaginal or infravaginal; spikelets with 4 glumes and one floret and no rachilla extension.................................................................................................................................................................. Chusquea

1. Culms hollow (except in a few species); nodes with only one bud; branching extravaginal or intravaginal; spikelets or pseudospikelets with 1–2 glumes and 2–12 florets, with a rachilla extension..............................................................................................2

2. Rhizomes leptomorph; two subequal, divergent branches per node ............................................................................. Phyllostachys

2. Rhizomes pachymorph; branching pattern various but not consisting of two, subequal, divergent branches per node....................3

3. Plants armed with sharp branch thorns (except in Guadua inermis ); culms with a band of short, soft white to tan hairs above and below the nodes, (except in G. longifolia ) .............................................................................................................................. Guadua

3. Plants unarmed, lacking branch thorns; culms without band of short, soft white to tan hairs above and below the nodes...............4

4. Midculm nodes with distinctly fan-shaped (apsidate) bud and branching patterns...........................................................................5

4. Midculm nodes lacking distinctly fan-shaped bud and branching patterns, with one dominant main branch and 2 to numerous smaller branches.................................................................................................................................................................................6

5. Culms often robust and thick-walled, internodes often scabrous or mottled (or both); culm leaves with blades pseudopetiolate and reflexed, narrower than the sheath summit, and deciduous; synflorescences often comb-like and racemose with short-stalked, somewhat stout and inflated spikelets, each with one or two functional florets ........................................................ Merostachys sp.

5. Culms usually weak and thin-walled, with smooth, non-mottled (uniform) internodes; culm leaves with blades erect (never reflexed), confluent with the sheath summit, and persistent; synflorescences generally loosely flowered and racemose with sessile, slender, non-inflated spikelets, each with several functional florets ........................................................................... Rhipidocladum

6. Culms 5–15 cm in diameter, 5–20 m tall; one main branch and numerous smaller branches per node, the bigger more than 2 times wider than the smaller; culm leaves with auricles................................................................................................................. Bambusa

6. Culms 0.3–6 cm in diameter, 2–10 m tall; branching various but if one main branch present per node, then only 2–6 smaller branches per node present; culm leaves usually lacking auricles.......................................................................................................7

7. Culms small-sized (2–4 m tall, 0.3–1.5 cm in diameter); foliage leaf blade undersurfaces with a narrow green stripe along one margin.................................................................................................................................................................................................8

7. Culm medium-sized (2–10 m tall, 1–6 cm in diameter); foliage leaf blade undersurfaces uniform in color, without a narrow green stripe along one margin......................................................................................................................................................................9

8. Culms clambering to scandent, 0.3–0.5 cm in diameter ; culm leaves with blades reduced, sheaths bearing small fimbriae at the summit; branching with 3 to 5 branches per node, geniculate at first internode; Chiapas .......................... Arthrostylidium excelsum

8. Culms erect, 1–1.5 cm in diameter ; culm leaves with blades well developed, sheaths bearing well developed, curly fimbriae at the summit; 1 branch per node, straight; Chiapas, Guerrero and Veracruz ...................................................................... Aulonemia laxa

9. One branch per node, diameter of the branches at mid-culm equal or one-half of the diameter of the main culm; lemmas abaxially glabrous or hispid at the apex; growing in tropical rain forest and cloud forest..................................................................... Olmeca

9. Three main branches per node (rarely one or two or six), diameter of the branches at mid-culm less than one quarter of the diameter of the main culm; lemmas abaxially pubescent, scabrous or scabrid; growing mainly in tropical dry forest or humid pine-oak forest and xerophytic scrub.................................................................................................................................................................. Otatea