Chascolytrum sect. Hildaea

Taxonomic key for the species of Chascolytrum sect. Hildaea

1. Lemmas with a gibbous back distinct from the margins, back papillate.............................................................................................. ......................................................... C. uniolae ( Nees von Esenbeck 1829: 494) Essi, Longhi-Wagner & Souza-Chies (2011: 329)

- Lemmas without a gibbous back distinct from the margins, or only slightly distinct, back glabrous or strigose, smooth or rough ... ...........................................................................................................................................................................................................2.

2. Lemmas with a length/width ratio less than 2.5, cordate at the base ................................................................................................3.

- Lemmas with a length/width ratio more than 2.5, attenuate at the base ...........................................................................................5.

3. Paleas villose ............................. C. juergensii ( Hackel 1915: 76) Essi, Souza-Chies & Longhi-Wagner (2010: 153) var. juergensii

- Paleas glabrous ..................................................................................................................................................................................4.

4. Spikelets oblong, subcylindrical; lemmas apices acuminate to caudate .............................................................................................. ......................................................................................................... C. latifolium Essi, Souza-Chies & Longhi-Wagner (2010: 151)

- Spikelets elliptic, laterally compressed; lemmas apices obtuse to acute, occasionally mucronate...................................................... ......................................................................... C. calotheca ( Trinius 1831: 414) Essi, Longhi-Wagner & Souza-Chies (2011: 328)

5. Lemmas strigose................................................................................................................................ C. juergensii var. angustilemma

- Lemmas glabrous...............................................................................................................................................................................6.

6. Paleas puberulous on the back, more than 3/4 the length of the lemmas......................................................................... C. serranum

- Paleas glabrous on the back, less than 3/4 the length of the lemmas ............................................................................. C. ambiguum