Australian Grasses. 31 



ISACHNE, R. 



(From two Greek words signifying " equal" and a " glume.") 



SPTKELETS two-flowered, both flowers hermaphrodite, or the upper female, 

 or the lower male, small, in loose panicles ; the rhachis of the spikelet 

 articulate above the empty glumes, glabrous, and not produced above the 

 flowering ones. Glumes unawned, convex, faintly nerved, two outer empty 

 ones nearly equal ; flowering ones of a firmer consistence, closely sessile, or 

 the upper one slightly raised. Palea as long as the glume. Styles distinct. 

 Grain enclosed in the hardened glume and palea, and free from them. 



Isachne australis, E. Br. (Southern species.) " Swamp Millet." 

 Stems rather slender, decumbent, creeping, and rooting at the lower nodes, 

 ascending to 1 foot or more. Leaves lanceolate, rough with a minute pubes- 

 cence. Panicle loose, spreading, ovoid in circumscription, 1| to 3 inches 

 long, with numerous filiform branches. Spikelets all pedicellate, nearly 1 line 

 long. Outer glumes quite glabrous. Lower flower usually male, with a 

 glabrous glume, the upper female, shortly stipitate, with the glume usually 

 minutely and slightly pubescent; the rhachis slightly dilated and articulate 

 immediately under the upper glume. Palea as long as the glume. Grain 

 enclosed in the hardened glume and palea, but free from them. 



This perennial grass is generally found growing by the sides of streams, 

 and on swampy lands in the coastal districts of Queensland, New South 

 Wales, and Victoria. Mr. Bentham says it is found also in tropical Asia 

 from Ceylon and the Peninsula to the Malayan Archipelago and South 

 China. In the settled districts in the Australian Colonies it is not nearly so 

 abundant as it was a few years ago, especially in places where cattle have 

 had easy access. When collecting botanical specimens a few days ago I had 

 a striking prooE of this. In a district where it used to grow abundantly 

 not very long ago the only place that I observed it growing luxuriantly was 

 protected on one side by a steep bank, and on the other side by a fence. 

 Not only are horses and cattle remarkably fond of the " swamp millet," but 

 pigs eat it with avidity. It is well worth conservation on wet lands in the 

 coastal districts of all the Australian Colonies, and I can highly recommend 

 it also for planting on the banks of rivers or dams to protect them from 

 injury by heavy rains or floods. Its underground stems and roots form a 

 perfect mat in a very short time, and when it becomes well established in 

 the soil it is not easily dislodged. It will bear submersion for a few days 

 without the slightest injury. When this grass is allowed to grow undis- 

 turbed for a time ifc procluces plenty of seed, so that there would be no 

 difficulty in collecting a quantity for dissemination in different parts of the 

 country. It should be sown in the spring of the year. This grass will also 

 propagate readily from pieces of the root if planted during the spring of the 

 year. Its seeds usually ripen during November, December, and January. 



Reference to plate. A, Spikelet. B, Showing the sessile male and stipitate female floret 

 with the outer glumes removed, c, Male floret. D, Female floret. E, Grain, back and front 

 views. All variously magnified. 



