486 ' ECOLOGICAL STUDY OF SALTMARSH VEGETATION. 



Calamagrostis are aberrant in the saltmarsh, as they are essen- 

 tially mesophytie, but the demand for moisture is more insistent 

 than distaste for the salinity of the marsh or the acidity of the 

 swamp . 



The Spurrey, Spergularia rubra Camb., supports a fluctuat- 

 ing growth on the salt plain among the detritus heaps, ocea 

 sionally forming a limited sward on the more habitable parts 

 of the plain. This cosmopolitan species, a low procumbent suc- 

 culent herb with varicolored flowers (red to white) of a dull 

 hue, is of annual duration in cold regions but attains a biennial 

 growth in our local marshes. It is joined in this station by a 

 yellow. Marsh Daisy, C'otula coronopifolia L., a shortly rhizomatic 

 perennial with a wide range, chiefly maritime, in both the Old 

 and New World, whose bright flowers are conspicuous among 

 the dull surroundings. In the area in which they are asso- 

 ciated, these herbs are not competitive, the conditions precluding 

 a strong growth in either formation, and their diverse root 

 systems seek nutrition at different levels. The Cotula does not 

 venture as far on the dry plain as its associate, its larger and 

 more luxuriant colony in the vicinity of the pools and soaks 

 (Plate xxiv., fig 15) disclosing its partiality for moisture, and 

 its more rank growth in the fluvial mud on the side of the 

 drainage channel presents prima facie evidence of its inclination 

 for a less saline habitat. The Spurrey requires less moisture 

 and is more strictly halophytic. The Cotula was present in all 

 the marshes visited, but the Spergularia was not so well repre- 

 sented, the stretches of salt plain at Cook's River in the neigh- 

 bourhood of Tempe railway station carrying the largest colonies 

 noted . 



Gruppy (13, p. 540) notes little or no floating capacity in 

 .the seeds of the maritime forms of Spergularia rubra, with or 

 without winged seeds, even after prolonged drying. [Seeds of 

 saltmarsh plants, one year old, tested by the writer, sank at once.] 



During the testing of the buoyancy of the achenes of C'otula 

 coronopifolia, a quantity of a gelatinous adherent mucus was 

 emitted when the seeds were immersed. The presence of this 

 species in extra tropical South America, New Zealand, and 

 South Africa, and its capacity for dispersal by gulls and other 

 sea-birds owing to the adherence of its sticky fruits to their 

 feathers, gives it a measure of significance in relation to the 

 Antarctic problem discussed by Guppy (15) and Hedley.* 



*The Palaegeographic Relations of Antarctica. 



