DICHOGAMY. 311 



In protogynous dichogamy it is no uncommon thing for the stigma to project 

 from the flower already fitted to receive pollen whilst the petals are still closely 

 shut, the whole flower having the appearance of a bud. This happens in the 

 Curled Pondweed (Potamogeton crispus, figured on p. 148), in Asphodels (e.g. 

 Asfphodelus albus), in Woodrushes (e.g. Luzula nivea), in Elms (e.g. Vlmus campes- 

 tris), in the Plantain (e.g. Plantago media), in several Rhododendrons (e.g. Rhodo- 

 dendron Ghamoicistus), in Cortusa, Deutzia, and many other plants. On the other 

 hand, many plants with protandrous dichogamous flowers are known where the 

 pollen is shed from the anthers while the petals are still folded as in the bud. On 

 opening the ripe bud of Grucianella stylosa (figured on p. 265), it can be seen at 

 a glance that the anthers have already dehisced some little time, and have 

 deposited their pollen under the dome of the closed bud on the thickened warty 

 surface at the end of the style. In the flowers of Rhododendron hirsutum, the 

 pollen falls from the anthers while still in the bud, and the same may be observed 

 also in many Composites, Campanulacese, and Papilionaceous flowers. 



We are not yet in a position to say whether protandrous or protogynous species 

 are the more abundant, although the dichogamy of thousands of plants has been 

 investigated. By generalizing on this subject one is liable to fall into very great 

 error. It would be particularly dangerous to generalize prematurely on the results 

 which have been obtained from the examination of many species of a genus, or 

 many genera of a family, and to consider them to hold good for the whole group, 

 for most genera contain some protandrous species, even when the majority of them 

 are protogynous, and vice versd. Liliaceous plants are described as protandrous in 

 most Botanical books, but in reality many of the genera and species are incom- 

 pletely protogynous (ATnaryllis, Asphodelus, Golchicum, Erythronium, Leucojv/m, 

 Liliwrn Martagon, Narcissus poeticus, Ornithogalum umbellatum, Scilla, Trillium, 

 &c.). Among the Umbelliferse, which are usually stated to be all protandrous, 

 there are quite a number of protogynous genera and species, as, for example, 

 JEthusa, Astrantia, Gaucalis, Eryngium, Hacquetia, Pachypleurum, Sanicula, 

 Scandix, and Turgenia. This also applies to the Saxifrages: the majority, of 

 course, are protandrous, but some of them, viz. Saxifraga androsacea and peltata 

 are decidedly protogynous. The large-flowered species of Crane's Bill (Geranium 

 argenteum, livid.wm, pratense, sylvaticum) are protandrous, the small-flowered 

 (Geranium coluinhinum, lucidv/m, pusillum, RobertianuTn) are protogynous. In 

 the Scrophulariacese the genera Digitalis and Penstem,on are protandrous, and the 

 genera Linaria, Pcederota, Phygelius, Scrophularia, Veronica protogynous. Of 

 species belonging to Boraginaceae some are protandrous (e.g. Borago, Echium), 

 others protogynous (e.g. Gynoglosswm, Lithospermum). In Ranunculacese the 

 genus Aconitum, is protandrous, while the genera Adonis, Anemone, Atragene, 

 Glematis, and Posonia are protogynous. In the Gentian family some are pro- 

 tandrous, viz. Swertia perennis, Gentiana asclepiadea, ciliata, cruciata, Frceliohii, 

 Pannonica, Pneum,onanthe, pumctata, enxd prostrata; others, esipecially Menyanthes 

 trifoliata, Gentiana Bavarica, Germanica, glacialis, Rhoetica, and vema are 



