4 Andropogon. GR AMINE AE. 55 



than the 2nd, which is keeled, the 3rd small and hyaline ; flowering glume also small and 

 thin, with a long terminal bent and twisted awn ; palea minute or none ; barren spikelets 

 awnless. Erect perennial grasses, with leafy stems. 



A. Spikelets in pairs, or the terminal ones in 3's, and 

 arranged in spikes. 

 B. Spikes 2 or more, clustered at or near the summit of 

 the stem. 

 C. Articles of the spike with a translucent channel or 

 furrow between the thickened cilia te- villous 

 margins ; spikes numerous A. intermedins 1. 



C. Articles of the spike opaque ; lowest sessile spikelets 



barren. 

 Lowest glume hairy on back as well as at summit A. sericeus 2. 

 Lowest glume glabrous on back A. annulatus 3. 



B. Spikes 2 together, densely silky-hairy within or just 

 above a leafy sheathing bract. 



D. Spikes usually erect, awn prominent A. exaltatus 4. 



D. Spikes finally reflexed ; awn very short A. bombycinus 5. 



A. Spikelets mostly in 3's (1 sessile and fertile between 2 

 pedicellate barren ones), arranged in a loose panicle. 



E. Spikes reduced to 1 triplet of spikelets A. Gryllus 6. 



E. Spikes composed of several triplets or pairs A. halepensis 7. 



1. A. intermedius, R. Br. Blue Grass. An erect grass ; nodes bearded ; ligule 

 ciliolate, usually with long hairs behind it ; spikes 3-7 cm. long, 3 to over 20 in number, 

 pedunculate on an elongated axis and sometimes forming a panicle 10 or 12 cm. long ; 

 spikelets light-colored or purplish ; lowest glume obtuse, 7-9 nerved, ciliate on margins 

 and villous at base, otherwise glabrous, sometimes pitted on back ; awn 15-20 mm. long. 



Far North. Dec. -June. 



2. A. sericeus, R. Br. Erect grass ; nodes bearded ; ligule glabrous, but with long 

 hairs rising from the blade behind it ; spikes 2-7, sessile at the summit of the stem, 4-6 

 cm. long, densely clothed with silky hairs ; the lowest sessile spikelets barren ; lowest 

 glume with 7 to 9 nerves not reaching to its summit, hairy on the lower part of the back 

 and also with long hairs seated on tubercles at the summit ; awn about 2 cm. long. 



Sturt River (perhaps introduced in this locality) ; North and Far North. Dec.-Apl. 



3. A. annulatus, Forsk. Very near the preceding, but the clothing of the spikes is 

 not so dense, and the lowest glume is glabrous on the back, except for the tuft of hairs 

 on the callus and the long tubercle-seated hairs at the summit. Usually found here in 

 the var. humilis, Benth., which has 3-5 spikes, shorter than in the type (1^-2^ cm. long) 

 and most of the leaves with scattered, tubercle-seated hairs. 



Near Oodnadatta and Lake Fro me. Dec.-Apl. 



4. A. exaltatus, R. Br. Scent-grass. A handsome scented grass, 30 cm. to 2 m. high ; 

 leaves with long narrow points ; ligule long, glabrous ; nodes glabrous ; spikes twin or 

 rarely 3 together, emerging from a sheathing bract about as long as they, 2-2| cm. long, 

 densely silky -villous owing to the long hairs arising from the pedicels and articles of the 

 rhachis, erect or the lower ones sometimes spreading, forming together a narrow panicle ; 

 lowest glume glabrous, with 2 winged marginal nerves ; flowering glume 2-lobed ; awn 

 about 1^ cm. long. 



Flinders Range from Crystal Brook northwards ; Far North. Nov. -June. 



5. A. bombycinus, R. Br. Silky Heads. Near the preceding, but the leaves have not 

 the long points and the panicle is shortly branched ; sheathing bracts about as long as 

 the 2 spikes, which are finally bent downwards ; awn inconspicuous (about 1 cm. long), 

 very slender. 



Near Gawler ; Murray lands ; Far North. Dec. -June. 



6. A. Gryllus, L. Rather tall almost glabrous grass ; ligule very short, ciliate ; panicle 

 loose, of simple whorled capillary branches, each terminating in a spike reduced to 3 

 spikelets, 1 sessile and fertile and 2 male and pedicellate ; a tuft of reddish hairs at base 

 of each spike ; fertile spikelet 6-10 mm. long, lowest glume rigid, acute, 5-7 nerved, the 

 2 lateral nerves almost muricate ; 2nd glume awned ; flowering glume notched, with a 

 long bent awn ; lowest glume of pedicellate spikelets awned. — Chrysopogon Gryllus, Trin. 



Far North. Nov. -June. 



* 7. A. halepensis, (L.), Sibth. Johnson Grass. Tall glabrous grass, with stout stems 

 downy or glabrous at the nodes ; leaves flat ; panicle loose, pyramidal ; terminal spikelets 

 in 3's, the lower ones usually twin ; 2 outer glumes of fertile spikelet stiff, equal, pubescent, 



