36 PBAGTIGAL GUIDE TO GARDEN PLANTS 



are termed palmate or digitate (Glossary, fig. 50) ; or from opposite 

 sid^sof the midrib like a feather, when they we pinnate (fig. 85). The 

 leaflets of pinnate leaves may be divided once, twice, or more times. 

 "When the leaflets arise from one another on each side of the middle 

 lobe, they are called pedate, as in the Christmas Eose (Helleborus). 

 There is great variation, and as a rule two or more terms are employed 

 to describe the shape of a leaf, but the main forms will be found illus- 

 trated in the Glossary, pp. 1-18. 



THE FLOWER 



The botanist regards the parts of a flower as so many leaves specially 

 modified for certain purposes. An ordinary flower is composed of 

 (i.) sepals (the calyx) ; (ii.) petals (the corolla) ; (iii.) stamens (andrce- 

 cium) ; (iv.) carpels or pistil (gynoecium). The sepals and petals are 

 often absent altogether : sometimes one, sometimes another. As a rule 

 they form the most conspicuous and showy part of the flower, and their 

 natural duty is supposed to be to attract insects to search for honey and 

 thus disturb the pollen and fertilise the pistils or carpels. The stamens 

 and carpels are the essential parts of the flower, vyithout which it is 

 impossible to obtain seed. The stamens contain pollen in the little sacs 

 or bags at the apex called anthers shown at fig. 9 in the Glossary. 

 Insects are useful in brushing this pollen against the sticky top (the 

 stigma) of the pistil. The pollen is sometimes ripe before the stigma, 

 and vice versa, and it thus happens that flowers are not often fertilised 

 with their own pollen. In this way the pistils in one flower may be 

 fertilised with pollen from another, and if the species are difi'erent a 

 ' hybrid ' has been effected, or a ' cross ' if the plants are of the same 

 species. Seeds obtained from a plant thus crossed do not exactly 

 reproduce the characters of the parents, although the differences may 

 be very slight. 



Sometimes the same flower contains both stamens and pistil, when 

 it is said to be hermaphrodite. "When a flower contains stamens only 

 or pistils only on the same plant, it is said to be monoecious, as in the 

 Cucumber (p. 1156), Marrow (p. 1155), Begonia (p. 462). But when 

 male and female (or staminate and pistillate) flowers are borne on dif- 

 ferent plants, they are said to be dioecious, as in the Aucuba (p. 476) 

 and "Willow (p. 802). Very often flowers are without stamens and 

 pistils, and are termed neuter or sterile, as in the cultivated forms of 

 the Guelder Eose (p. 480) and the Hydrangea (p. 429). 



Double Flowers. — Cultivation often plays havoc with the stamens 

 and pistils. These become more or less suppressed, and (as showing 



