14. Setaria. GRAMINEAE. 61 



* 15. P. crus-galii, L. Cockspur Grass ; Barnyard Grass. Annual with ascending 

 stems, glabrous except the inflorescence ; leaves broad and long, without a ligule ; panicle 

 contracted, of numerous sessile suberect spikes ; spikelets crowded in 4 irregular rows 

 on one side of the bristly rhachis of the spike, ovoid, acute, 3-3| mm. long, with 

 bristly hairs on the nerves ; lowest glume broad, 3-nerved, not half as long as the spikelet ; 

 2nd and 3rd glumes equal, mucronate or awned, the 2nd 5-nerved, the 3rd 7 -nerved and 

 enclosing a palea ; fruiting glume smooth and shining. 



A weed in most places ; almost cosmopolitan. Dec.-Apl. 



14. SETARIA, Beauv. 

 (Latin. seta, a bristle : the spikelets are surrounded by stiff bristles.) 

 Spikelets with the bisexual flower and sometimes a male one below it, crowded in a 

 spikelike panicle ; outer glumes 3, the 1st small, and the 2nd usually shorter than the 

 3rd ; flowering glume and palea of Panicum. Spikelets subtended by a unilateral cluster 

 of persistant scabrous bristles. 

 A. Spikes rather short and dense. 



Flowering glume strongly rugose S. glauca 1. 



Flowering glume almost smooth S. viridis 3. 



A. Spikes longer and appearing whorled. 



Teeth of bristles reflexed S. ve ticillata 2. 



Teeth of bristles erect S. macrostachya 4. 



* 1. S. glauca, (L.), Beauv. Erect, pale-green annual; ligule of hairs and sometimes 

 there are also long hairs near base of leafsheath ; panicle spikelike, dense, 2-8 cm. long ; 

 bristles yellow or reddish -yellow, denticulate with erect teeth, several at the base of each 

 spikelet, 2nd glume shorter than the 3rd, which contains a palea ; fruiting glume trans- 

 versely wrinkled. 



Settled districts and probably introduced there. Dec. -Apl. — Temperate and subtropical 

 countries. 



* 2. S. vertieillata (L.), Beauv. Resembles the preceding, the panicle to 10 cm. long 

 and not so dense, expecially near the base, where the spikelets appear as if whorled ; 

 bristles green or purplish during flowering, 1-3 below each spikelet and with the small 

 teeth pointed downwards along the bristle ; 2nd and 3rd glumes almost equal and as long 

 as the flowering glume, which is almost smooth, or rugulose under the lens. 



Settled districts. Dec. -Mar. — Temperate and subtropical countries. 



* 3. S. viridis (L.), Beauv. Closely resembles S. glauca, with a similar compact panicle, 

 and several bristles with erect teeth, but the fruiting glume is shining and almost smooth, 

 and the 2nd and 3rd glumes are nearly equal ; leafsheaths ciliate, with rather long hairs 

 near the summit. 



River Murray district and South-East. Dec.-Apl. — -Temperate and subtropical 

 countries. 



4. S. macrostachya, H. B. et K. Resembles S. vertieillata, but has stouter stems and 

 longer though slender spikelike panicles (6-20 cm.), bristles 1 or 2 under each spikelet 

 and with erect teeth ; fruiting glume rugulose under the lens. 



From Farina northwards. Spring. 



15. CENCHRUS, L. 



(Kenkhros, Greek name for Millet.) 



* 1. C. tribllloides, L. Bur Grass. Glabrous annual ; leafsheaths loose ; ligule short, 

 ciliate ; spike terminal 5-10 cm. long ; spikelets sessile, with 1 bisexual flower, singly 

 or 2 together within a globular pubescent involucre of numerous bristles, united so as to 

 form in fruit a hard bur about 8 mm. long, beset with barbed spines ; outer glumes 3, 

 the lowest small ; flowering glume and palea of Panicum. 



A North American weed which appeared at Renmark and other places on the Murray 

 about 1910. Dec. -Mar. 



16. PENNISETUM, Rich. 

 (Latin penna, a feather ; seta, a bristle : alluding to the plumose bristles ) 



* 1. P. villosum, R. Br. Perennial with narrow serrulate leaves ; panicle cylindrical, 

 about 5 cm. long ; spikelets with 1 fertile flower, solitary or 2-5 together, each spikelet 

 surrounded by an involucre of long slender bristles, plumose in the lower half, the peduncle 

 falling off with the spikelets and bristles ; outer glumes 3, the 1st and 2nd small, the 3rd 

 containing a male flower ; flowering glume with a bisexual flower. 



An ornamental grass which has become naturalised near towns. — Abyssinia. Summer. 



17. PLAGIOSETUM, Benth. 

 (Greek plagios, oblique ; Latin seta, a bristle : alluding to the unilateral bristles.) 

 1. P. refractum (F. v. M.), Benth. Glabrous grass, with narrow leaves and a ligule of 

 silky hairs ; spikelets with 1 fertile flower, the upper spikelets solitary with flat pedicels 



