106 



Tribe v. — Stkeptatherze. 



Sub-tribe i. — Stipacese. 



48. Aristida. | 49. Stipa. 



48. ARISTIDA. 



Spikelets one-flowered on filiform pedicels, or nearly sessile in a 

 terminal panicle, the rhachis of the spikelet articulate above the two 

 outer glumes. 



Glumes three, narrow ; two outer usually persistent, keeled, empty, 

 and unawned ; terminal or flowering glume narrow, rigid, rolled round 

 the flower, entire, with a terminal trifid awn. 



Talea small, enclosed in the flowering glume. 



Styles distinct. 



Grain narrow, enclosed in the hard upper glume but free from it, 

 the whole falling off with the stipes and awn as in Stipa. 



All Australian species glabrous, with. con volute more or less subulate 

 leaves. 



Fungus found on Aristida sp. — TJstilago segetum, Bull. 



Section I. — Arthratherum. — Awn articulate on the glume, entire 

 and spirally twisted below the branches ; flowering glume much shorter 

 than the outer ones. 



Awn about 1^ inches below the branches, which vary from 1^ to 2J 



inches 2. A. slipoides 



Awn -| to f-inch below the branches, which vary from 1 to 3 inches 3. A. arenaria, 



Section II. — Chsetaria. — Awn not articulate, and divided to the 

 glume into three branches, the glume itself when barren sometimes 

 twisted, but not the awn ; flowering glume about as long or longer than 

 the outer ones. 



Panicle short, broad and dense ; glumes \ inch long ; awns long ... 4.-4. Behriana 



Panicle branches very long, at length spreading, with few spikelets 



on long pedicels ; glumes at least ^ inch long 5. A. leptopoda 



Panicle loose, at length pyramidal ; pedicels short ; outer glumes 



2 to 3 lines long ; flowering glume much longer; awns short... 6. A. vagans 



Panicle narrow, rather loose ; outer glumes as long as the flower- 

 ing one. 



Glumes scarcely 3 lines ; awns under \ inch long 7. A. ramosa 



Glumes 4 to 5 lines long ; awns f to 1 inch long 8. A. calycina 



Panicle narrow, dense ; spikelets sessile and crowded on the short 

 branches ; glumes 3 lines, or the flowering one rather longer ; 

 awns 4 to 6 lines 9. A. depressa 



2. Aristida stipoides, R. Br. 



Botanical name. — Aristida, from the Latin arista, the beard of an 

 ear of corn ; stipoides, from two words, stipa, oidos (Greek for like, 

 or similar to), signifying resembling the genus Stipa. 



