The New York Botanical Garden


Dennis Wm. Stevenson

Vice President for Laboratory Research
Editor, Botanical Review

Ph.D., University of California
Davis (1975)
Expertise: Cycads, Monocots, Genomics


My major research interests in the past few years have focused upon the evolution and classification of the Cycadales (cycads) and their placement in seed plant phylogeny. To this end I am conducting research on various facets of the biology of the Cycadales and Gnetales. These facets include reproductive biology, anatomy, cytology, molecular systematics, as well as taxonomic monographs and treatments of these groups for various floras being prepared for the neotropics. These research interests are being pursued by an active field program, particularly in the neotropics, to survey population sizes and demographics, to understand phenology, to study the recently discovered insect pollination biology of cycads and Gnetum. As part of this field program, live plants are also collected for laboratory research and for breeding purposes in order to try to save the cycads from extinction. I have recently expanded the scope of this program to include the paleotropic species of the cycads to produce a monograph of all Cycadales in collaboration with Ken Hill of the Royal Botanic Gardens Sydney. In addition, I have a collaborative research program with Gloria Coruzzi of New York University on the biology,syntheisis, and genetic control of the nonprotein amino acid, BMAA, which is implicated in Guam Dementia. I am part of the Plant Genomics Consortium and am conducting research, with the other consortium members, on the origin, development, and modification of the seed with a focus on the integuments and arils as well as heterospory. My other major research interest is the systematics of the monocots, particularly, the Commelinidae. The topics under investigation include developmental floral morphology, embryology, and inflorescence structure because this basic information is incomplete or unknown for many of these families. These data are being combined with gene sequence data to generate phylogenetic hypothesis on the origin and classification of the monocots.

Selected Publications

Stevenson, D.W. 1988. "Strobilar ontogeny in the Cycadales." In: Leins, P., P. Endress, and S. Tucker, eds. Aspects of Floral Evolution. J. Cramer, Stuttgart. 205-224pp.

Loconte, H. and D. Stevenson. 1990. "Cladistics of the Spermatophyta." Brittonia 42:197-211.

Stevenson, D.W. 1990. "Morphology and Systematics of the Cycadales." Mem. N. Y. Bot. Gard. 57:8-55.

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