PREFACE.

for these reasons, as well as Annona Custard apple, Michelia, Gnetum, and Magnolia.

11. I would have gladly retained the classes of Monoecia Plants with separate male and female flowers on the same individual and Dioecia Plants with male and female flowers on separate individuals, either kept apart or contracted into one under the name Diclinia A term for plants with unisexual flowers, had it not been repugnant to nature itself, and if many difficulties in examining vegetables had not hindered that very thing. Cynomorium, Rhodiola Rose-root, the whorled Myriophyllum Water-milfoil, Coriaria, and Menispermum often have hermaphrodite flowers Flowers containing both male and female reproductive organs, and thus, according to the method received from LINNAEUS, they ought to have been referred to the class Polygamia Plants bearing hermaphrodite and unisexual flowers on the same or different individuals. Of the two species of Callitriche Water-starwort, one is monoecious, while the other is hermaphrodite. The same is also found with Ruscus racemosus Alexandrian laurel, which is furnished with hermaphrodite flowers. Urtica Nettle occurs as both monoecious and dioecious. Populus Poplar indeed more often bears dioecious flowers, yet I have also seen monoecious ones. Likewise, in Cliffortia, I have not infrequently found dioecious flowers and often monoecious ones at the same time. Among the dioecious species of Salix Willow, there are one or two which enjoy hermaphrodite flowers. Mercurialis Mercury is monoecious among the ambiguous types. Very often in our gardens Spinacia oleracea Spinach occurs as dioecious, yet I have often seen it both monoecious and hermaphrodite. Clutia pulchella is often dioecious, yet not rarely also monoecious. In its native soil, Rhodiola is commonly found to be dioecious; a female plant also persisted alone for more than fifty years original: "decem lustra" - a lustrum is a five-year period in the Academic Garden at Uppsala without a male, which, having now been introduced there, produces hermaphrodite flowers every year—