136 Rhodora [May 
18. Economic FORMATION, Siophytes. 
Habitat: cultivated fields, orchards and grounds. Species planted 
and cared for by man to supply his food, clothing, shelter or to be 
used for ornament or other purposes in his economic life. 
The various cultivated plants. 
19. FuNnGoID FORMATION. Siophytes. 
Habitat: growing on living or dead organisms, from which they 
derive their sustenance. Parasites and saprophytes, mainly fungi. 
Cuscuta Gronovii, Willd. Epiphegus Virginiana, Bart 
Monotropa uniflora, L. Aphylion uniflorum, Gray. 
M. Hypopitys, L. Conopholis Americana, Wallr. 
Fungi various. 
BIBLIOGRAPHY. 
(Some of the works consulted in the preparation of this paper.) 
Christ, D. H. Vegetation und Flora der Canarischen Inseln. 
Engler's Botan. Jahrb. 6 : 458—526. 
Contejean, Ch. Géographie Botanique, influence du terrain sur 
la végétation. Paris, 1881. 
Costantin, J. Les végétaux et les milieux cosmiques. Paris, 
1898. 
Coulter, J. M. Plant Relations. New York, 1899. 
Coville, F. V. Botany of the Death Valley Expedition. Cont. 
U. S. Nat. Herb. vol. 4. Washington, 1893. 
Daveau, Jules. La flore littorale du Portugal. Bull. Herb. 
Boissier, 4:209-313. Genève, 1896. 
De Candolle, A. Géographie botanique raisonnée. Paris, 1855. 
Drude, O. Manuel de géographie botanique. French trans. by 
G. Poirault. Paris, 1897. 
Drude, O. Ueber die Principien in der Unterscheidung von Veg- 
etationsformationen. Engler’s Bot. Jahrb. 11:21-51. Leipzig, 1889. 
Gray, Asa. Manual of the Botany of the Northern United States, 
6th Edition. New York, 1889. 
