Elodea is a member of the monocotyledonous natural order Hydrocharideae.
It would appear, then, that the orchid flower differs from the more general monocotyledonous type in the irregularity of the perianth, in the suppression of five out of six stamens, and in the union of the one stamen and the stigmas.
The number of species of orchids is greater than that of any other monocotyledonous order - not even excepting grasses - amounting to 6000, contained in 400 genera.
In 1677 he described and illustrated the spermatozoa in dogs and other animals, though in this discovery Stephen Hamm had anticipated him by a few months; and he investigated the structure of the teeth, crystalline lens, muscle, &c. In 1680 he noticed that yeast consists of minute globular particles, and he described the different structure of the stem in monocotyledonous and dicotyledonous plants.
Some plants, which in most points of their structure are monocotyledonous, yet have reticulated venation; as in Smilax and Dioscorea.