T. Holm — North American Species of Stellaria. 315 



Art. XXXV. — Method of Hibernation and Vegetative Re- 

 production in North American Species of Stellaria; by 

 Theo. Holm. (With six figures in text, drawn from nature 

 by the author.) 



Although the Caryophyllacece, and especially the Alsinew, 

 exhibit such a remarkably wide geographical distribution 

 throughout the northern hemisphere, being able to thrive in 

 the most northerly points* and at the highest elevationsf at 

 which flowering plants are known to exist, they are, neverthe- 

 less, rather poor in biological types. 



Neither the aerial nor the subterranean organs have become 

 modified to any great extent that might lead us to suspect the 

 extraordinary vitality possessed by some of these species. The 

 habit is strikingly uniform ; the diagram of the flower, the 

 structure of the inflorescence, the foliage, and the ramification 

 of the shoot is almost identical, or at least very little modified 

 in a number of these plants. In the perennial Silenew, for 

 instance, the frequent structure of the shoot with its compact 

 rosette of leaves and persisting primary root shows very little 

 variation among the arctic, the alpine, and lowland represen- 

 tatives ; among the Alsinece we observe in some genera 

 exactly the same morphological structure as in the Silenew, 

 while in others there is a marked tendency to spread by pro- 

 ducing creeping rhizomes so as to enable the individual to take 

 rapid and wide possession of the soil. In the genus Stellaria, 

 for instance, there are some perennial species, in which the 

 shoot demonstrates certain characteristic modifications so far 

 as concerns " hibernation and vegetative reproduction," and 

 these we intend to illustrate by a few examples, inasmuch as 

 the literature does not give but a very scant information about 

 the biology of these plants. The diagnoses of the species as given 

 in the Synoptical Flora;}; are undoubtedly very exact, and may 

 be sufficient for the determination, but mostly the floral organs 

 have been considered ; we believe, however, that the vegetative 

 organs in several cases might be of some importance also, not 

 only as a means of distinguishing the species, but also for the 

 sake of giving a more complete demonstration of the particular 

 habit of some of these plants. 



* Cerastium alpinum L. has been collected at 82° 50', Stellaria longipes 

 Goldie and Alsine verna Bartl. at 82° 27', and Alsine Groenlandica (Retz.) 

 Fenzl at 81° 42' N. L. 



f Arenaria Stracheyi Hook, grows at an elevation of 19,200 ft. in Tibet ; 

 Cerastium trigynum Vill., Stellaria subumbellata Edgew., and Sagina pro- 

 cumbens L. are reported from the Himalayas at an elevation of 16,000 to 

 17,000 ft. 



JFasc. II, p. 208, 1895-97. 



