38 THE PLANT WORLD. 



cal and a rather compact cluster of white tiowers on a naked scape. 

 S. Davurica has fan-shaped leaves, with the l)road apex coarsely 

 toothed. S. niralis which grows near j^atches of snow on the moun- 

 tains and anions the holders of the jjlacial moraines, looks much like 

 our eastern Vh'yiulensiK^ but has a denser flower-cluster. The flowers 

 of its ally, S. hieracifolia, are of a dark purple-brown. .S*. Jrvonchialu 

 has thick, coriaceous, pectinate leaves in dense rosettes. 



S. oppositifolia, representing the small section Porphyrion, 

 grows, when the soil is dry and sandy, in a very compact rounded 

 cushion, often almost perfectly hemispherical. But on dripping rocks 

 it spreads out, the slender stem-branches become elongated and the 

 leaf -rosettes less dense. The solitary flowers are violet, an un- 

 common color in the genus. 



Showiest of all the Saxifrages known in Alaska, and probably for 

 that matter, in the world, are two species with large single flowers of 

 a bright golden yellow, the exact color of buttercup tiowers. These 

 are 8. Hircidus and S. JJageUarls, the latter peculiar for its tiliform, 

 strawberry-like offsets which bud at the end and thus propogate the 

 plant. Hardly less showy than these is 6'. serpyllifolia^ for its blos- 

 soms, albeit smaller, are much more numerous. This species decorates 

 the tundra of St. Matthew and other islands with a myriad of little 

 golden stars. It has the caespitose habit and almost leathery leaves of 

 Diapensia Lapponica. 



THE WATER HYACINTH IN FLORIDA. 

 By a. H. Curtiss. 



WE have had some notable examples of late years of the inva- 

 sion of man's domain by species of the animal kingdom 

 whose destructiveness and rapid increase has been most 

 alarming, and whose small size has rendered them the more difficult to 

 cope with. But something more remarkalde than the invasion of the 

 gypsy moth, English sparrow, rabbit or mongoose was witnessed a 

 few years ago in Florida, when the destruction of her inland connnerce 

 was threatened by a species of the vegetation kingdom. Insects and 

 quadrupeds must have food, and in (piest of it they can move rapidly 

 over a large territory, l^ut plants, except by the dispersal of their 

 seeds, are stationary. Even floating ai^uatics are so normally, their 

 habitats being still waters or streams Avhere they can obtain anchorage 



