Chusquea, Kunth, 1822

Ruiz-Sanchez, Eduardo, Mejía-Saulés, Teresa & Clark, Lynn G., 2014, Chusquea nedjaquithii (Poaceae: Bambusoideae, Bambuseae, Chusqueinae), a new endemic species from Oaxaca, Mexico, Phytotaxa 184 (1), pp. 23-30 : 24-25

Key to the species of Chusquea present in Mexico based on vegetative characters

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 Clark, Corte ́s & Cházaro (1997: 225)

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 Ruiz-Sanchez & Clark (2013: 3)

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 never 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

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

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 Hackel (1903: 153)

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 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 Soderstrom & Caldero ́n (1978: 158)

7. Subsidiary branches 20–50 per 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 Soderstrom & Caldero ́n (1978: 156)

8. Subsidiary branches 2–6 per node......................................................................................................................................................9

8. Subsidiary branches (5–)10–100 per node .......................................................................................................................................11

9. Branching infravaginal, never extravaginal or intravaginal; plants scrambling and hanging from vegetation ................................... .................................................................................................................................................................. C. glauca Clark (1989: 95)

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; endemic to Volcan Acatlán , Veracruz, Mexico............................................................................. C. enigmatica Ruiz-Sanchez, Mejía-Saulés & Clark (2014: 20)

10. Foliage leaf blades 12.5–24.5 cm long, 2.1–4 cm wide; culms 1–2 cm in diameter, 2–8 m tall; Chiapas, Mexico to Honduras........ ................................................................................................................................ C. lanceolata Hitchcock ex Morton (1935: 145)

11. 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 Fournier (1886: 132)

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

12. 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 ) ..................................................................................................................................13

12. 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.........................................................................................................................................16

13. Central bud circular; internodes 27–50 cm long ............................................................................. C. galeottiana Munro (1868: 59)

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

14. Foliage leaf blades 0.7–1.5 cm wide, L:W = 5–8.5; culms climbing and hanging; tropical or montane forest................................... ....................................................................................................................................................... C. simpliciflora Munro (1868: 54)

14. 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 ...............................................................................................................................................................................................15

15. 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

15. 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 Swallen (1940: 209)

16 Culms erect, sometimes arching toward the apex; foliage leaf blades yellowish-green, abaxially strongly tessellate........................ ................................................................................................................................................................... C. aperta Clark (1987: 74)

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

17. Subsidiary branches 80–100 per 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 Swallen (1940: 30)

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

18. Foliage leaf blades abaxially glabrous .............................................................................................................................................19

18. Foliage leaf blades abaxially pilose (completely or only toward the base)......................................................................................20

19. Central bud circular; subsidiary branches 6–14 per node, usually rebranching; foliage leaf blades narrowly ovate .......................... .............................................................................................................................................................. C. muelleri Munro (1868: 65)

19. Central bud triangular; subsidiary branches 10–25 per node, usually not rebranching; foliage leaf blades linear lanceolate............. ............................................................................................................................................. C. repens Clark & Londoño (1991: 327)

20. Subsidiary branches 5–10 per node; foliage leaf blades 1.1–1.8 cm wide..................... C. cortesii Ruiz-Sanchez & Clark (2013: 7)

20. Subsidiary branches 10–30 per node; foliage leaf blades 0.3–1.1 cm wide.....................................................................................21

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

21. Culms 0.5–1 cm in basal diameter, arching and scandent; Guerrero, Michoacan, Chiapas ................................................................. ............................................................................................................................... C. nelsonii Lamson-Scribner & Smith (1897: 16)