Studies in Seed Germination. 
The Genus Marah (Megarrhiza), Cucurbitaceae. 
BY 
ARTHUR W. HILL. M.A., F.L.S., 
Assistant Director , Royal Gardens , Kew. 
With Plate V and two Figures in the Text. 
S OME dry prickly fruits, which appeared to belong to a species of 
Echinocystis, were received at Kew in 1908 from Mr. F. R. S. Bal- 
four of Dawyck, having been collected by him in the arid Sierra Nevada 
region of California. The seeds, which were unlike those of any known 
species of Echinocystis, quickly germinated and were found to exhibit 
a type of germination similar to that of the Californian ‘ Big root Megar- 
rhiza calif ornicas described and figured by Asa Gray 1 and Darwin. 2 
A further supply of seeds of this plant and also seeds of allied species from 
California were obtained through the kindness of Mr. Balfour and other 
correspondents, and an examination of their mode of germination has 
yielded some results of interest. 
In order to ascertain the botanical identity of the seeds originally 
received, the specimens of Echinocystis and allied genera were obtained 
on loan from the Smithsonian Institution and examined by Mr. S. T* 
Dunn. 3 
The seeds were found to belong to the genus Marah , Kellog {Megar- 
rhiza (Ton*.), S. Wats.), which is morphologically quite distinct from 
Echinocystis , Coignaux. 
In this remarkable genus the underground tubers are said often to 
reach the size of a man’s body. 4 
It is of interest to find that the systematic grounds on which Marah was 
separated from Echinocystis are supported and strengthened by morpho- 
logical considerations, since not only is the underground tuber a feature 
peculiar to Marah , but the type of germination is essentially geophilous, 
1 Asa Gray : American Journal of Science, vol. xiv, 1877, pp. 21-4, and the Botanical Text 
Book, Pt. I, Structural Botany, ed. 6, 1879, pp. 20, 21. 
2 Darwin, C. : The Power of Movements in Plants. 1880, pp. 81-3. 
3 Dunn, S. T. : The Genus Marah , in Kew Bulletin, 1913, pp. 145-53, and p. 238. 
4 Hall, H. M., in Univ. Calif. Publ. Botany, vol. i, 1902, p. 19. 
[Annals of Botany, Vol. XXX. No. CXVIII. April, 1916.] 
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