48 Xotcs on Marsiica I'iUosa. 



pubescence of this species, and ])roba1)ly also of .1/. I'cstila. is a char- 

 acter which is (le]KMi(lent on environmental factors. 



\Jarsilca vlllosa is now very rare in Hawaii, and is not rei)re- 

 sented in nian\- herbaria. The habitals for the i)lant are old taro 

 ]iatches. places where i'dlcciisin aiitiiitionnii was cnltivated. Aecord- 

 in^' to Robinson" all si)eeiinens ol it in the I'.erlin I lerbarinni are 

 sterile, and those collected b\' l\eni\- have narrower leal1et> and a 

 more comjiact rootstalk than those collected b\' Cdiamisso. 



A station for this ])lant was fotmd in I'alolo valley, within the 

 cit\' limits of Honolnln. in a small, poorh' drained area formerly 

 taro ]iatches. but now overgrown with several species of ""rass and 

 sedg-e, among which are a few large Kiawe trees (Prosopis jitHHora). 

 Among- the sedges was an abundance of Blacocharis palustris (L) 

 R. Brown, which was recorded from Oahu by Knnth, though its 

 existence in the Hawaiian group was doubted by Hillebrand." 



When the station was first visited in March, an area of about 

 two acres was flooded with water, on the surface of which were 

 floating thousands of Alarsilea leaves. The plants gathered at that 

 time were all sterile and were glabrous in all parts except the nodes, 

 which varied from nearly glabrous to somewhat woolly (PI. XIII). 

 The length of the petioles varied directly with the depth of the 

 water in which the plants were growing — long petioles in deep 

 water, short |)etioles in shallow water — and were of unusual length 

 on plants growing in water amongst grass. Plants taken from shal- 

 low water near the edge of the pond had petioles ranging in length 

 from 3.5 to 4.0 centimeters; whereas many growdng in water with 

 pjass had petioles of 23 centimeters in length. In jiroportion as the 

 water dried up with the advance of summer, the plants became 

 more and more conspicuously rusty woolly at the nodes, aufl the 

 under side of the leaves became pubescent with whitish hairs. 

 Finally when the water had disappeared, during the last week in 

 April of the same year, the ]')lants were found t<i be densely rusty 

 woolly at the nodes, with occasionally a few scattered hairs along 

 the rhizome. fh\ a dr\- hummock a single fruiting s])ecimen was 

 found. 



' Robinson, W. J., op. cit. 



' Hillebrand, Wm., Flora of the Hawaiian Nlands, p. 474, if 



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