240 A NATURALIST IN THE PACIFIC chap. 



alterations which the appendages of the achene may have undergone 

 in the cases of other genera. With most species there are usually 

 two or three teeth or short awns, but in some species these are 

 obsolete, and in others they are long and stout. 



Bearing these facts in mind we should hesitate to rely too much 

 on the present condition of the achenes in the other genera as an 

 indication of the fitness for dispersal of the fruits of their ancestors. 

 In one genus, Campylotheca, which may be regarded as among the 

 youngest of the genera, the achenes are provided with barbed or 

 hooked awns which cause them to adhere as tenaciously to one's 

 clothes as in the case of those of Bidens, an allied genus. In 

 Fitchia, the Tahitian genus, which may be looked upon as one of 

 the oldest of the Pacific genera of Compositse, the achene is 

 furnished with two long awns or setae, which, as Drake del Castillo 

 observes, recall those of Bidens. The achenes of the other Hawaiian 

 genera, as regards their fitness for dispersal in plumage, may be 

 said to give less definite indications. In some, as in Dubautia and 

 Raillardia, there is a typical pappus of ten to twenty long hair-like 

 bristles. In others again, as in Wilkesia and Argyroxiphium, the 

 pappus is much reduced, and in some species of Lipochaeta it is, as 

 above remarked, quite obsolete. 



The chances of the achenes of the parent plants having in 

 some cases been originally transported to the islands in the 

 plumage of birds would be increased by a bird making its nest of 

 the plant-materials or amongst the plants themselves, or by its 

 pecking at the fruit-heads. In our own time different species of 

 the grouse family on the slopes of the Californian and Columbian 

 mountains make their nests on the ground under the shade of 

 Artemisia bushes and find a portion of their sustenance in their 

 fruits. Artemisias also form one of the features of the vegetation of 

 the Hawaiian uplands ; but since they present only specific 

 differentiation they are referred to a later era. Yet it will be on the 

 slopes of the Rocky Mountains and of the Californian Sierra 

 Nevada, amongst the " sage-brush " and the grouse, that we may 

 have to stand when we look in thought across the Pacific towards 

 far distant Hawaii and ask ourselves whence came its tree-like 

 Raillardias, its shrubby Dubautias, its tall Wilkesias, and the 

 silvery Ahinahinas (Argyroxiphium). 



It is possible that in some genera the achenes have, or had, a 

 means of adhering to plumage through a " sticky " secretion, such 

 as is sometimes found with Lagenophora, an Hawaiian genus of 

 the next era, and also with the weed-plant Adenostemma viscosum ; 



