Chusquea sect. Longifoliae

Ruiz-Sanchez, Eduardo, Romero-Guzman, Rafael, Flores-Argüelles, Alejandra, Ortiz-Brunel, Juan Pablo & Clark, Lynn G., 2021, Chusquea contrerasii and C. guzmanii (Poaceae, Bambusoideae, Bambuseae, Chusqueinae), two new endemic species from Jalisco, Mexico, Phytotaxa 497 (3), pp. 285-297 : 286-287

Key to the species of Chusquea sect. Longifoliae in Mexico (based on vegetative and reproductive characters)

1. Culms robust, 2–6 cm in diameter, solid becoming fistulose with age; culm leaf blades persistent; subsidiary buds at mid-culm nodes 80–100; spikelets 10.4–20.6 mm long .................................................................................................................. C. longifolia

1. Culms thinner, 0.5–1 cm in diameter, solid; culm leaf blades deciduous; subsidiary buds at mid-culm nodes 5–50; spikelets 4.5–12.6 mm long...............................................................................................................................................................................2

2. Culm leaf sheaths with the overlapping margin fused above the base; foliage leaf blades tessellate; synflorescence an open panicle; glume III apiculate, glume IV subulate ................................................................................................................................ C. aperta

2. Culm leaf sheaths with the margins free; foliage leaf blades not tessellate; synflorescence a narrow congested panicle; glumes III and IV awned or mucronate................................................................................................................................................................3

3. Branches 5–10 per node; foliage leaf blades 1.1–1.8 cm wide, oblong-lanceolate; synflorescences 7–13 cm long; lemmas pubescent ............................................................................................................................................................................. C. cortesii

3. Branches 10–31 per node; foliage leaf blades 0.4–1 cm wide, linear-lanceolate; synflorescences 2.5–8 cm long; lemmas scabrous or pubescent........................................................................................................................................................................................4

4. Lemmas scabrous, awned................................................................................................................................................... C. nelsonii

4. Lemmas pubescent, acuminate or mucronate.....................................................................................................................................5

5. Glume III 1.6–2.2 mm long; glume IV 2–2.6 mm long, glabrous, apex mucronate; lemma 3.8–4.3 mm long, mucronate................ .......................................................................................................................................................................................... C. guzmanii

5. Glume III 3.1–3.8 mm long; glume IV 3.4–4.4 mm long, scabrous, apex awned; lemma 6.4–7.3 mm long, acuminate.................... ........................................................................................................................................................................................ C. contrerasii