274 PATAGONIAN EXPEDITIONS '. BOTANY. 



9. Basilar sheaths mediocre. Bract half as long as spike. Female scales obtuse, deciduous. 



(3) C. aphylla. 



Basilar sheaths large, the upper produced. Bracts twice as long as spike. Female scales 

 acute, persistent. C. molince. 



10. Rhizome cespitose. Culms all flowering. Leaves reduced. C. berteroani. 

 Rhizome bearing also sterile culms. Leaves developed. n. 



1 1 . Culm rigid, exceeding the rigid leaves. Spike globose, many-flowered. C. andina, 

 Culm slender, nearly hid in sheaths. Spike subglobose, few-flowered. (29) C. patagonica. 



12 (from i). Spikes numerous. 



Spikes sexually mixed. 13. 



Spikes sexually distinct. 37. 



13. Hyparrhene. Spikes basally male. 14. 

 Acrarrhene. Spikes apically male. 16. 



14. Hyparrhence. 



Spikes crowded into a head. Utricle winged, long-rostrate (Uncinia). 



(26) C. Icporina L. (C. macloviana d'Urv.). 

 Spikes 5-6, ovate, contiguous. Utricle plano-convex, margined. Rostrum 2-toothed. 



(31) C. propinqua N. & M. 

 Spikes remote. Utricles short-rostrate. 15. 



15. Scales white. Spikes small. Utricles not winged. (9) C. canesccns L. or (36) siiirilis d'Urv. 

 Scales blackish. Spikes larger. Utricle spinulose-winged. (4) C. atropicta Steud. 



1 6. Acrarrhence. 



Spikes more or less sessile. 1 7. 

 Spikes 4, upper one androgynous, lower female and stalked. Stigmas 2. (25) C. lechleri. 



Spikes long-stalked. 3 1 . 



17. Spikes remotish, short-petioled, long-bracted. C. untguensis. 

 Spikes crowded in a head. 18. 



1 8. Head involucrate. Rostrum incurved. 19. 

 Head exinvolucrate. Rostrum straight. 23. 

 Head with a long leafy bract : rostrum cleft. (13) C. divisa Huds. 



19. Sheath cross-wrinkled. Spike long, compound. C. brongniartii Kth. 

 Sheath smooth. Spike short, simple. 20. 



20. Utricles tubercled, nervose, and spongiose. (6) C. bonariensis Dsf. 

 Utricles smooth. 2 1 . 



2 1 . Spike oblong. Utricle nervose, spongiose. (7) C. bracteosa Ktze. 

 Spike ovate or ovate-oblong, not very nervose. 22. 



22. Spike 2' cm., crass. Utricles green-margined. C. soraira Kth. 

 Spike I cm., less crass. Utricles green- or fulvous-margined. (23) C. involncrata Bt. 



23 (from 1 8). Head long. Utricle narrow, ciliate-margined. Rostrum long. Culm hid among 



leaves. C. reichii Krk. 



Head ovate or triangular. Utricle broader, not ciliate-margined. 24. 



24. Utricle membranaceous, not crass. 25. 

 Utricle suberose-incrassate. 26. 



25. Culm terete, compressed, incurved. Leaves plicate, not thick. Spike globose, ovate, male 



flowers generally concealed. Scales broad-ovate, mucronate. (22) C. incurva Lightf. 



