Chusquea Kunth, 1822

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 : 14-16

Chusquea Kunth

Rhizomes pachymorph or less commonly leptomorph, sometimes amphimorph; culms solid or rarely hollow, often fistulose with age, erect, scandent, or clambering, usually arching apically and hanging; culm leaf sheaths well developed, without auricles or fimbriae at the summit, sometimes the margins fused together at the base, oral setae absent; blades erect, persistent or deciduous; branching extra-, infra- or intravaginal; nodes with multiple and dimorphic buds, one usually larger central bud subtended or flanked by few to numerous smaller, subequal subsidiary buds, these constellate, linear or verticillate in arrangement; synflorescences paniculate or rarely racemose; spikelets terete or compressed laterally or dorsally, consisting of 4 glumes, 1 bisexual fertile floret, floret lanceolate to ovate, and no rachilla extension; palea more or less equal to the lemma; lodicules 3, stamens 3; stigmas 2; fruit a basic caryopsis ( Fig. 4A–F ).

1. Internodes hollow...............................................................................................................................................................................2

1. Internodes solid, sometimes becoming fistulose with age.................................................................................................................3

2. Internodes thin-walled; subsidiary buds/branches at mid-culm nodes numerous, verticillate, subequal; foliage leaf blades abaxially glabrous .................................................................................................................................................................... C. perotensis Endemic to Mexico; Oaxaca and Veracruz; 2000–2600 m .

2. Internodes thick-walled; subsidiary buds/branches at mid-culm nodes 5–16, constellate, of two sizes; foliage leaf blades abaxially ciliate at the blade base................................................................................................................................................. C. matlatzinca Endemic to Mexico; Michoacán; 2650–2750 m .

3. Subsidiary buds/branches at mid-culm nodes numerous, verticillate or nearly so.............................................................................4

3. Subsidiary buds/branches at mid-culm nodes few to numerous, constellate or linear but not encircling the node...........................8

4. Central bud circular or oblate; apex of culm leaf sheath short and more or less broad.....................................................................5

4. Central bud triangular; apex of culm leaf sheath narrow and elongate..............................................................................................6

5. Central bud circular, subsidiary buds arranged in a complete verticil in two or three rows of buds, more than 100 subsidiary branches per node; foliage leaf inner ligule 0.5–1 mm long .......................................................................................... C. liebmannii Mexico to Costa Rica; Pacific slopes of Mexico; 300–1400 m.

5. Central bud oblate, subsidiary buds not forming a complete verticil, in a single row of buds, with 13 to 17 subsidiary branches per node in two patches; foliage leaf inner ligule 5–10 mm long ...................................................................................... C. nedjaquithii Endemic to Mexico; Oaxaca; 1600 m .

6. Culms 3–5 cm in basal diameter, 10–20 m tall, erect to scandent at the tips; root thorns encircling the lower and middle nodes of culm and major branches, some root thorns usually present on upper nodes of culms and major branches ....................... C. pittieri Mexico to Panama; Chiapas; 1800–2200 m.

6. Culms to 2.5 cm in basal diameter, to 15 m tall, arching and clambering, not erect; root thorns usually absent, rarely a few present at mid-culm nodes..............................................................................................................................................................................7

7. Subsidiary branches 60–100 or more per mid-culm node, 0.3–0.5 mm in diameter, exserted more or less horizontally; foliage leaf blades 0.3–1.2 cm wide, L: W = 5.8–10, the base attenuate, the apex apiculate .............................................................. C. coronalis Mexico to Costa Rica ; Chiapas; 1200–1500 m.

7. Subsidiary branches 20–50 per mid-culm node, 0.6–0.9 (–1) mm in diameter, exserted more or less vertically; foliage leaf blades 0.3–0.7 cm wide, L: W = 8–16.5 (–23), the base attenuate to rounded-attenuate, the apex apiculate to subulate............. C. circinata Endemic to Mexico ; Pacific slopes of Mexico; 900–1900 m.

8. Subsidiary branches 2–6 per mid-culm node.....................................................................................................................................9

8. Subsidiary branches (5–) 10–100 per mid-culm node......................................................................................................................12

9. Branching infravaginal, never extravaginal or intravaginal; plants scrambling and hanging from vegetation ................... C. glauca Endemic to Mexico; Veracruz; 1900–2500 m .

9. Branching extravaginal or both extravaginal and intravaginal, never infravaginal; plants erect to arching and clambering.........10

10. Foliage leaf blades 10–11.7 cm long, 0.8–1.2 cm wide; culms 0.05–0.15 cm in diameter, 0.2–1 m tall...................... C. enigmatica Endemic to Mexico ; Veracruz (Volcán Acatlán); 1960 m .

10. Foliage leaf blades 12.5–24.5 cm long, 1.4–4 cm wide; culms 0.3–2 cm in diameter, 1.3–8 m tall; Veracruz, Puebla and Hidalgo states in Mexico to Honduras, but not found on Volcano Acatlán, Veracruz, Mexico....................................................................11

11. Branching both intravaginal and extravaginal on the same culm ; foliage leaf blades 1.4–2.8 cm wide; culms 1.3–2 m tall.............. ........................................................................................................................................................................................ C. gibcooperi Endemic to Mexico ; Hidalgo, Puebla, Veracruz; 1500–2400 m .

11. Branching strictly extravaginal; foliage leaf blades 2.1–4 cm wide; culms 2–8 m tall.................................................. C. lanceolata Mexico to Honduras; Chiapas; 2100–3000 m.

12. Branching intravaginal; subsidiary buds both flanking and subtending the central bud, forming a line extending up to half the circumference of the node; foliage leaf blades abaxially tessellate .................................................................................. C. bilimekii Endemic to Mexico: Estado de Mexico, Veracruz; 2700–3000 m.

12. Branching infravaginal or extravaginal; subsidiary buds strictly constellate, subtending or curving around the central bud; foliage leaf blades abaxially usually not tessellate.......................................................................................................................................13

13. Branching extravaginal, culm leaves often deciduous as branches develop; foliage leaf blades usually with an abaxial tuft of hairs at the base (sometimes lacking in C. sulcata )..................................................................................................................................14

13. Branching infravaginal; culm leaves usually persistent; foliage leaf blades abaxially glabrous, pilose or with scattered hairs but lacking a defined tuft of hairs at the base.........................................................................................................................................17

14. Central bud circular; internodes 27–50 cm long ........................................................................................................... C. galeottiana Endemic to Mexico; Guerrero, Oaxaca; 2300–2500 m .

14. Central bud triangular; internodes 10–22 cm long...........................................................................................................................15

15. Foliage leaf blades 0.7–1.5 cm wide, L:W = 5–8.5; culms climbing and hanging; tropical or montane forest.......... C. simpliciflora Mexico to Ecuador; Chiapas; 150 m.

15. Foliage leaf blades 0.3–0.9 cm wide, L:W = 8–30; culms erect and arching only at the apices to arching; montane or pine-oak forests...............................................................................................................................................................................................16

16. Culm leaf sheaths narrowed and elongate toward the apex, bottle-shaped; foliage leaf blade L:W = 8–16.5 (–23); culms arching; supranodal ridge a line, not prominent; sometimes a patch of subsidiary buds or branches present on the opposite side of the node from the main bud/branch complement............................................................................................................................. C. circinata

16. Culm leaf sheaths more or less triangular with rounded shoulders; foliage leaf blade L:W = (15–) 17–30; culms erect, arching at the apices; supranodal ridge prominent; buds/branches strictly constellate........................................................................ C. sulcata Mexico to Costa Rica; Chiapas, Oaxaca, Veracruz; 1650–2300 m.

17. Culms erect, sometimes arching toward the apex; foliage leaf blades yellowish-green, abaxially strongly tessellate......... C. aperta Endemic to Mexico; Oaxaca, Veracruz; 2300–2700 m .

17. Culms arching and scandent or trailing and clambering; foliage leaf blades green, abaxially not tessellate..................................18

18. Subsidiary branches 80–100 per mid-culm node; culms 2–6 cm in basal diameter, erect at the base and then arching to scandent; foliage leaf blades L: W = 16–33 ..................................................................................................................................... C. longifolia Mexico to Guatemala ; Chiapas; 2200–3000 m.

18. Subsidiary branches 5–30 per mid-culm node; culms 0.2–1 cm in basal diameter; arching to scandent or trailing and clambering; foliage leaf blades L:W = 6–20........................................................................................................................................................19

19. Foliage leaf blades abaxially glabrous.............................................................................................................................................20

19. Foliage leaf blades abaxially pilose (completely or only toward the base)......................................................................................21

20. Central bud circular ; subsidiary branches 6–14 per mid-culm node, usually rebranching; foliage leaf blades narrowly ovate.......... ............................................................................................................................................................................................ C. muelleri Endemic to Mexico; Veracruz; 1800–2300 m .

20. Central bud triangular ; subsidiary branches 10–25 per mid-culm node, usually not rebranching; foliage leaf blades linear-lanceolate ........................................................................................................................................................................................ C. repens Endemic to Mexico; Chiapas, Oaxaca; 2200–2700 m .

21. Subsidiary branches 5–10 per mid-culm node; foliage leaf blades 1.1–1.8 cm wide ......................................................... C. cortesii Mexico to Guatemala; Chiapas, Estado de México, Guerrero, Jalisco, Michoacán, Nayarit ; 1400–3000 m.

21. Subsidiary branches 10–30 per mid-culm node; foliage leaf blades 0.3–1.1 cm wide....................................................................22

22. Culms 0.2–0.3 cm in basal diameter, trailing and clambering; Chiapas and Oaxaca ........................................................... C. repens

22. Culms 0.5–1 cm in basal diameter, arching and scandent; Guerrero, Michoacán .............................................................. C. nelsonii Endemic to Mexico ; Guerrero, Michoacán; 2300–2700 m .

Figures

FIGURE 4. A. Chusquea circinata, nodal region, showing the central bud and smaller subsidiary buds. B. Chusquea galeottiana flowers (spikelets). C. Chusquea matlatzinca, showing red culms. D. Chusquea liebmannii habit. E. Chusquea cortesii showing its infravaginal branch pattern. F. Chusquea repens in the cloud forest. Photos by E. Ruiz-Sanchez.