BY A. a. Hamilton". 485 



Two annual grasses, Calamagrostis aemula Steud., found in all 

 the Australian States and New Zealand, and the curly, tufted 

 Lepturus incurvatus Trim, common on the Mediterranean littoral 

 and extending from India to Australia and New Zealand, are 

 frequently present on the detritus mounds, and scattered gener- 

 ally throughout the various formations bordering the salt plain. 

 The Calamagrostis is less halophytie than the Lepturus, extend- 

 ing to the fluvial formations and the moist meadow on the marsh 

 slopes, and frequently occurs among the rushes and sedges in a 

 freshwatei swamp. Both grasses establish colonies in the 

 formations of the permanent herbage, neither forming an inde- 

 pendent sward; a few tufts occasionally occupy a vacancy in a 

 suitable habitat. Their vertical roots do not compete with the 

 horizontal root systems of the grasses or other herbs with which 

 they are usually associated. The Lepturus frequently forms 

 extensive banded colonies in a sward of Sporobolus, Zoysia, or 

 Cynodon on the marsh margin, completing its life cycle before 

 the demand for space created by the spring activities of its 

 hosts becomes insistent, the disintegration of its colony provid- 

 ing a mulch of humus tor the permanent pasture which has 

 given it sanctuary, it is rarely taller than the herbage with 

 which it consorts and has to contend for aerial space and ac- 

 cess to the light. To obviate the danger of being overrun, the 

 outer stems of the Lepturus tufts curve laterally from the base, 

 pressing back the more yielding superstructure of its associates 

 and securing space for expansion and admission of the essential 

 illumination. The fruits of the Lepturus are embedded in 

 cavities in the rachis of the flower spike and the joints, which 

 separate at maturity, are floated by the tide into the surrounding 

 formations. 



The Calamagrostis, which rarely assembles in large patches, 

 lias a weak growth and is unable to spread among its associates. 

 The plants are compressed, their soft basal leaves yielding to the 

 pressure of the surrounding herbage, folding vertically around 

 the stem, and threading their way through the interstices to the 

 light. The stem rises above the sward to mature its plumed 

 floral panicle which bends when weighted with grain, resting on 

 the sward. Finally, the fruit-laden branches are snapped off 

 by the wind and collected into a ball which is blown over the 

 meadow or salt plain, scattering its seeds, simulating the Tumble 

 Weed of the "Western Plains. The broad soft leaves of the 



