68 THE FLOWER (DICLINISM, ETC.) 
each section of floral morphology dealt with. The beginner 
should work through each section with flowers in hand, 
dissecting, describing, and sketching ; after he has had some 
practice in this work he should go on to describe the flower 
as a whole 1 . 
Segregation of Sporophylls or grouping of each kind 
by itself, is characteristic of nearly all existing flowers except 
Selaginella &c. and must have occurred very early in the 
evolution. The sporophylls may be all in the same herma- 
phrodite 2 or bisexual ( $ ) flower, or may be in separate 
unisexual 2 flowers, the microsporophylls or stamens in male 2 
or staminate ( $ ), the megasporophylls or carpels in female 2 
or pistillate ( 5 ) flowers. In hermaphrodite flowers the 
carpels occupy the summit of the axis, and the stamens 
stand below them. 
Unisexual flowers occur in a number of Phanerogams, 
but in all but the Gymnosperms, the catkinate families, and 
perhaps a few others, they are probably derived from herma- 
phrodite ancestors, as is indicated by the male flower usually 
possessing rudimentary carpels, the female rudimentary 
stamens. Examples occur in Sagittaria, Rhamnus, Begonia, 
Aucuba, Bryonia, Petasites, Tussilago, &c. Other “distri- 
butions of sex ” are also found. 
Descriptive Terms, <S rV. Plant with both stamens and carpels in 
one £ flower, monoclinous , in separate S and ? flowers, diclinous ; S and 
? flowers on the same plant, monoecious , on separate plants, dioecious. 
Other complications are gynomonaecism ( $ and ? on the same plant, as 
in some Labiatae, Compositae, &c.), gynodicecism ( £ and ? on separate 
plants, as in Nepeta, Thymus, and other Labiatae, Plantago, many 
Caryophyllaceae, &c.), andromoncecism ( $ and S' on one plant, as in 
Veratrum), androdioecism ( $ and <? on separate plants, as in Dryas), 
tricecism ( $ , S , ? , each on its own plant, as in Silene sp.), polygamy 
( £ , S , ? , in various combinations on one or more plants, as in Rhus, 
Fraxinus, &c.). All these phenomena, except monoecism and dioecism 
1 The following works may be consulted with advantage: ( Morpho- 
logical ) Goebel, Organography of Plants , Entwicklungsgeschichte der 
Pflatizenorgane (in Schenk’s Handbuch der Botanik) ; Eichler, Bliithen - 
diagrammed Schumann, Morphologische Studien , Neue Untersuchungen 
iiber die Bliitenansckluss ; Payer, Organogenie de la Fleur ; Bower, 
Studies in the Morphology of Spore-producing Members (Phil. Trans., 
recent years) ; (. Ecological ) the books mentioned under Pollination 
on p. 58. 
2 These sex terms ought not to be applied to parts of the sporophyte, 
but are firmly established in botanical literature. 
