THE AMERICAN BOTANIST 135 



tree of thirty or forty feet. The young shoots copiously pro- 

 duce a glutinous exudation which covers the leaves as with a 

 layer of shellac. In both species the lovely, heavily-scented 

 flowers are terminal and solitary. 



Undoubtedly the crowning glories of Hawaii's floral 

 world are her unique woody Lobelias, of which there are nearly 

 one hundred species! Of the six genera, five are endemic, and 

 practically all of the species are endemic. The corollas of 

 these highly specialized and interesting plants are long, 

 curved, tubular, and deeply slit along the back. In one re- 

 markable monotypic genus, Brighamia, the corolla is salvar- 

 shaped, with a straight, entire tube three to five inches long. 

 In color the lobelia flowers are greenish white, cream, pale 

 pink to deep rose, lilac, purple, or dark bluish. The lighter 

 ones are often marked with darker stripes. Some of the in- 

 florescences attain great size, spreading out several feet from 

 the stem, and laden with flowers in various stages of develop- 

 ment. Many of our Hawaiian Lobelioideae are trees, ten to 

 thirty feet in height, with naked stems closely marked with 

 leaf-scars, branching sparingly, and the foliage crowded at the 

 ends of the thick branches. The lobelias occupy a wide variety 

 of habitats and elevations, but are largely restricted to the 

 humid forests, exposed rainy slopes and precipices, and other 

 distinctively hydrophytic regions. Many species are highly 

 precinctive. The range of variation and polymorphism is phe- 

 nomenal. Many forms are on the verge of extinction, or are 

 already extinct. The apparent over-specialization of the floral 

 structures strikingly reminds one of similar conditions among 

 certain orchid genera. Like many other elements in the 

 Hawaiian flora and fauna, the lobelias seem to be the vestiges 

 of a much more extensive primitive flora. 



