208 THE BOOK OF NATURE STUDY 



one. Its general features are, however, more those of a wind- 

 pollinated flower. Since the stigma is usually capable. of receiving 

 pollen at the time that this is being shed by the stamens of the 

 same flower, self-pollination is not prevented as it is in the 

 Ribwort Plantain. 



The small, dry fruit developed from the ovary after fertilisation 

 is of interest owing to the way in which it opens to liberate the 

 seeds. A circular split forms about one-third way up the fruit, 

 and the upper portion separates as a lid from the cup-shaped 

 lower part. Some of the seeds fall off with the lid, while others 

 remain for a time in the lower portion. 



The Rib wort Plantain (Plantago lanceolata) is similar in the main 

 features of growth and floral structure to the Greater Plantain, 

 but differs in details. It is represented in the accompanying 

 plate. There is a long, stout, tapering tap-root growing vertically 

 into the soil, and giving off thin lateral branches. The stout 

 main stem has no vegetative branches. It bears below the remains 

 of the leaves of former seasons, and farther up the present foliage- 

 leaves. The leaf -blade is narrower than in the Greater Plan- 

 tain, and the almost parallel main veins project very strongly on 

 the lower surface. The inflorescences, which develop from the 

 axillary buds, have a long, leafless, strongly ribbed stalk, six inches 

 to a foot in length, and at the summit a short spike of flowers. 

 The bracts are greenish, edged and tipped with brown, and each 

 has a single flower in its axil. The structure of the flower is 

 similar to that of the Greater Plantain. The way in which the 

 flowers open presents an important difference, however. The 

 opening begins with the flowers at the base of the spike, and pro- 

 ceeds towards the tip, and the different stages in the flowering 

 can be made out in a single inflorescence, though better if a 

 number of different ages are gathered and compared. It will 

 be found that the stigma matures first, projecting from the partly 

 closed flower. Only after the stigma has withered does the 

 flower open fully, and the stamens project and liberate their 

 dusty pollen. Self-fertilisation is thus prevented, and the flowers 

 are usually cross-pollinated by means of the wind. Inflor- 

 escences of various ages are represented in the plate. The 

 arrangements for preventing self-pollination and for facilitating 



