Chusquea sect. Swallenochloa

Refulio-Rodriguez, Nancy F., Klahs, Phillip C., Leandro, Thales D., Mcmurchie, Elizabeth K. & Clark, Lynn G., 2025, A new species of Chusquea subg. Swallenochloa (Poaceae: Bambusoideae) from the Peruvian upper montane forest, Phytotaxa 716 (4), pp. 231-247 : 240

Key to the species of Chusquea sect. Swallenochloa in Peru based on vegetative and reproductive features

1. Foliage leaf blades tessellate on both surfaces, mostly reflexed, the pseudopetioles flat with ciliate-pubescent margins.................. .......................................................................................................... C. intipaqariy Fadrique & Clark in Fadrique et al. (2019: 183)

- Foliage leaf blades not tessellate, ascending to erect, the pseudopetioles adaxially concave to keeled with glabrous margins........2

2. Spikelets with glume IV nearly equaling the spikelet length ................................................................. C. smithii Clark (1986: 107)

- Spikelets with glume IV no more than ¾ the spikelet length.............................................................................................................3

3. Spikelets falcate or slightly falcate.....................................................................................................................................................4

- Spikelets straight ................................................................................................................................................................................6

4. Spikelets with glumes III and IV and lemma awned; foliage leaf blades (1.5–) 1.8–3.9 (–4.2) cm wide ...................... C. gamarrae

- Spikelets with glumes III and IV and lemma acute to mucronulate; foliage leaf blades 0.1–0.25 cm wide......................................5

5. Spikelets with glumes I always absent and II usually absent; foliage leaf sheath summit extension truncate ........... C. depauperata

- Spikelets with glumes I sometimes absent and II always present; foliage leaf sheath summit extension acuminate.......................... ...................................................................................................................................................................................... C. robinfosteri

6. Spikelets with glumes III and IV and lemma mucronulate but blunt; foliage leaf blades V-shaped in cross section.......................... ........................................................................................................................................................ C. neurophylla Clark (1986: 105)

- Spikelets with glumes III and IV and lemma short-awned to awned; foliage leaf blades flat in cross section .................................7

7. Foliage leaf sheath summit with an extension; paleas with an apical tuft of short cilia .............. C. weberbaueri Pilger (1905: 146)

- Foliage leaf sheath summit without an extension; paleas without a conspicuous apical tuft of short cilia .......................................8

8. Foliage leaf blades 11.9–20 cm long, base rounded-attenuate; lemmas awned .......................... C. simplicissima Pilger (1905: 145)

- Foliage leaf blades (3.6–) 5–9 cm long, base truncate-cordate; lemmas short-awned........................... C. spicata Munro (1868: 60)