232 EuG. Warming. 



I have divided the following description into four sec- 

 tions, viz, 

 I. Morphology and Vegetative Propagation. 

 II. Leaf Anatomy. 



III. Adaptations to the Environments. 



IV. Flower Biology and Notes on Seed-production. 



I. Morphology and Vegetative Propagation. 



According to the duration of life, and the forms of the 

 vegetative shoots and the combinations of them, etc., I di- 

 vide the species — for the sake of a general survey — into 

 the following groups: — 



A. The Melandrium type. Spot-bound, ^ pollacanthic, 

 semi-rosette plants. 



B. The Silène acaulis type. Spot-bound species, of which 

 the long-shoots have short internodes, and narrow leaves. 



C. The Sagina nodosa type. Spot-bound, pollacanthic 

 species, with shoots which must be described as long-shoots 

 with elongated internodes, although the basal leaf-pairs are 

 close-set. Monopodia! rosette shoot, at least in some of the 

 species. No propagation by means of aerial runners. 



D. The Cerastium alpinum type. Spot-bound, pollacan- 

 thic species, the shoots of which also usually have shorter 

 internodes at the base, and must be called long-shoots, but 

 which have terminal flowers (sympodia), and on which aerial 

 runners are developed. Vegetative propagation can take 

 place by means of layers. 



E. The Cerastium arvense type. Species with shoots like 

 those of D, but which have both aerial and subterranean 

 runners, and a more constant vegetative propagation by 

 means of runners. 



* Spot-bound, that is, they have no horizontal shoots or runners, 

 with which they can form "layers" (see Warming, 1884). 



