Chusquea subg. Swallenochloa (McClure, 1973) Clark, 1997

Pianissola, Evandro Machado, Parma, Daniele F., Santos-Gonçalves, Ana Paula & Clark, Lynn G., 2018, Two new species of Chusquea subg. Swallenochloa (Poaceae: Bambusoideae: Bambuseae) from Minas Gerais, Brazil, and complete description of C. caparaoensis, Phytotaxa 358 (3), pp. 235-250 : 248

Key to the species of Chusquea subg. Swallenochloa in Brazil (based on vegetative and flowering specimens)

1. Foliage leaf sheaths deciduous from the lower nodes of the subsidiary branches.............................................................................2

- Foliage leaf sheaths persistent............................................................................................................................................................8

2. Central bud/branch flanked by 1 ‒ 3 subsidiary buds/branches on each side in one linear row; branching intravaginal....................3

- Central bud/branch subtended by 1 ‒ 2 rows of subsidiary buds/branches, or subtended by 4 ‒ 5 tiers and flanked by 4 ‒ 5 subsidiary buds/branches; branching extravaginal..............................................................................................................................................4

3. Spikelets 6 ‒ 7.1 mm long, glumes III and IV (3.3 ‒) 3.8 ‒ 5.6 mm long, including the awn; foliage leaf blades on reproductive branches 0.18 ‒ 0.4 mm wide.............................................................................................................................................. C. fruticosa

- Spikelets 4.3 ‒ 4.9 mm long, glumes III and IV 2.8 ‒ 3.2 mm long; foliage leaves (0.5 ‒) 0.8 ‒ 1 mm wide ...................... C. windischii

4. Spikelets 1.5 ‒ 3 mm wide; central bud/branches flanked by slightly smaller subsidiary buds/branches, and subtended by 4 ‒ 5 rows of medium to small sized subsidiary buds/branches; foliage leaves with inner ligules 0.2 ‒ 0.5 (‒ 1) mm long, truncate, and sheaths mottled............................................................................................................................................................................. C. juergensii

- Spikelets 0.9 ‒ 1.6 mm wide; central bud/branch subtended (not flanked) by 1 or 2 rows of subsidiary branches; foliage leaves with inner ligules 0.5 ‒ 4.0 mm long, and sheaths uniform in color, not mottled........................................................................................5

5. Lemma subulate; central bud nearly circular; culm leaf blade narrowly triangular, erect becoming reflexed, caducous; subsidiary branches 4 ‒ 10 per node.................................................................................................................................................. C. nudiramea

- Lemma mucronate; central bud triangular; culm leaf blade triangular, erect, persistent; subsidiary branches 15 ‒ 80 per node......................................................................................................................................................................................................................6

6. Lemma and palea incanous abaxially; central bud/branch subtended by 1 ‒ 2 more or less linear rows of subsidiary buds/branches; foliage leaf blades 0.18 ‒ 0.25 cm wide ....................................................................................................................... C. caparaoensis

- Lemma and palea glabrous abaxially; central bud/branches subtended and partially encircled by 1 ‒ 2 rows of subsidiary buds/ branches; foliage leaf blades (0.2 ‒) 0.5 ‒ 0.9 (‒ 1.2) cm wide.............................................................................................................7

7. Spikelets 4.3 ‒ 6.3 (‒ 7.5) mm long, 0.9 ‒ 1.4 mm wide, the palea and lemma subequal; synflorescences (1.5 ‒) 2 ‒ 4 cm long, narrow to open; foliage leaf blades (0.3 ‒) 0.5 ‒ 0.9 (‒ 1.2) cm wide, L:W = (4 ‒) 7.7 ‒ 15; smaller subsidiary branches 15 ‒ 40 per node ......... .................................................................................................................................................................... C. mimosa subsp. mimosa

- Spikelets (5.5 ‒) 6 ‒ 7.5 mm long, 1.1 ‒ 1.6 mm wide, the palea and lemma subequal or more often the palea overtopping the lemma; synflorescences 1 ‒ 3 cm long, narrow or only the lower branches and pedicels reflexed; foliage leaf blades (0.2 ‒) 0.4 ‒ 0.7 cm wide; L:W = 10.6 ‒ 23.7; smaller subsidiary branches 45 ‒ 80 per node .............................................................. C. mimosa subsp. australis

8. Branching extravaginal.......................................................................................................................................................................9

- Branching intravaginal.....................................................................................................................................................................10

9. Spikelets 4.7 ‒ 5.5 mm long; synflorescences 1 ‒ 1.5 cm long; subsidiary branches 1.5 ‒ 4 cm long, 30 ‒ 60 per node, the central branch usually not developing; supranodal ridge obscure; culms 0.5 ‒ 1 m tall ....................................................................... C. microphylla

- Spikelets 5.4 ‒ 6.9 mm long; synflorescences 1 ‒ 4 cm long; subsidiary branches 3 ‒ 15 cm long, (12 ‒) 20 ‒ 45 per node, the central branch usually developing, robust; supranodal ridge prominent; culms 1 ‒ 2 (‒ 3.5) m tall......................................... C. heterophylla

10. Glumes I and II minute, scale-like, <1/20 the spikelet length..........................................................................................................11

- At least glume II developed,>1/20 the spikelet length....................................................................................................................12

11. Spikelets 6.2 ‒ 8.7 mm long; glumes III and IV abaxially finely pubescent; synflorescences 2 ‒ 5 cm long .................... C. baculifera

- Spikelets 4.3 ‒ 4.9 mm long; glumes III and IV abaxially glabrous; synflorescences 1.5 ‒ 2 cm long.............................. C. windischii

12. Spikelets 7.7 ‒ 8.7 mm long; synflorescences 4 ‒ 6.5 cm long....................................................................................... C. hatschbachii

- Spikelets 4.7 ‒ 7.1 (‒ 8.1) mm long; synflorescences 0.5 ‒ 4 cm long.................................................................................................13

13. Foliage leaf blades 0.8 ‒ 1.1 cm wide ........................................................................................................................... C. sclerophylla

- Foliage leaf blades 0.06 ‒ 0.6 cm wide..............................................................................................................................................14

14. Subsidiary buds/branches flanking the central bud/branch..............................................................................................................15

- Subsidiary buds/branches subtending the central bud/branch..........................................................................................................16

15. Glumes I and II 0.6 ‒ 0.8 mm long, ca. 1 / 10 the spikelet length; palea 2-nerved; foliage leaf blade 0.06 ‒ 0.15 cm wide, L:W = (25 ‒) 33 ‒ 60 .................................................................................................................................................................................... C. nutans

- Glumes I and II 0.2 ‒ 0.4 mm long, <1 / 15 the spikelet length; palea 4-nerved; foliage leaf blade 0.2 ‒ 0.6 wide, L:W = 10 ‒ 13 ............ ....................................................................................................................................................................................... C. riosaltensis

16. Glume IV apex mucronate; foliage leaf blades L:W = 17 ‒ 31; culm leaf persistent, shorter than or equaling one internode, sometimes up to 1.3 times the internode length......................................................................................................................... C. pinifolia

- Glume IV apex subulate, foliage leaf blades L:W = (6.75 ‒) 8.0 ‒ 17.3 (‒ 19); culm leaf deciduous, extending for (1.4 ‒) 2 ‒ 3 times the internode length ......................................................................................................................................................... C. imbricata