780 THE SUBDIVISIONS OF THE VEGETABLE KINGDOM. 



the families above enumerated may be placed in several groups according to the 

 form of that structure. In the first group the hypanthium is short as compared 

 with the floral-leaves, and dries up or detaches itself when the fruit is ripe 

 (Papilionaceaä, Csesalpinese, Mimosea3, Amygdalese, Rhamnaceae); the pistil is simple. 

 In the second group the hypanthiuni is flat, and bears the floral-leaves and stamens 

 on its margin, and several separate unilocular carpels arranged in spirals in the 

 middle of its surface; it does not fall off when the fruit ripens. In the third gi-oup 

 the hypanthium undergoes further growth when the fruit ripens, and is converted 

 into an envelope surrounding the nut-fruits, which have developed from the 

 separate carpels in the interior of the pitcher-shaped cavity of the hypanthium 

 (Agrimoneee, Roseae; see fig. 438*^, and fig. 208^'^' p. 74). In the fourth group the 

 multilocular pistil is adnate to the hypanthium which surrounds it entirely, and is 

 converted into a fleshy pericarp (Pomacese; see fig. 208*'^'''> p. 74). In the fifth 

 group only the lower half of the 2-carpellary gynaeceum is adnate to the hyp- 

 anthium, so that its upper half projects above the hypanthium, which is clothed by 

 the calyx-tube (some of the Saxifragacese). In the sixth and last group the short 

 hypanthium is only adnate at the base to the multicarpellary, actinomorphic 

 gynaeceum (Crassulaceae, Styracaceae, &c.). These groups are by no means shai-ply 

 defined, and the links connecting them are again described as special families. It 

 is also worthy of note that honey-secreting tissues in the flowers exhibit extreme 

 variety of form and position; sometimes they constitute a fleshy lining to the inner, 

 i.e. the upper-surface of the hypanthium (several Dryadeae), sometimes a swelling 

 round the base of the ovary (several Saxifragaceae), sometimes an annular ridge, or 

 a group of separate wart-like glands, which are seated on the edge of the extremely 

 short hypanthium, and are looked upon as metamorphosed stamens (Crassulaceae). 



Amongst Caesalpineae, Pomacece, and Hamamelidaceae are many species of 

 arboreal growth, and amongst Mimoseae, Amygdaleae, Roseae, Spiraeeae, Rhamnaceae, 

 and Hydrangeaceae are large numbers of shrubs and under-shrubs. The majority of 

 the herbaceous plants of this alliance occur in the families of Papilionacese, Dryadeas, 

 Agrimonere, and Saxifragaceae. The Caesalpineae include several climbing lianes, 

 the Papilionaceae afford numbers of instances of switch-shrubs, and the Mimoseae 

 exhibit many shrubs with phyllodes. Amongst the Saxifragaceae and Crassulaceae 

 many species with thick leaves (see vol. i. p. 327) occur. Cephalotus is insec- 

 tivorous (see vol. i. p. 131). Compound pinnate or digitate foliage-leaves occur 

 especially in Rubeae, Dryadeae, Roseae, PapiUonaceae, Caesalpineae, and Mimoseae 

 (see vol. i. p. 533), whilst entire foliage-leaves are found particularly in Amyg- 

 daleae, Styracaceae, Crassulaceae, Philadelphaceae, and Rhamnaceae. The flowers of 

 Papilionaceae and Caesalpineae, and of some of the Saxifragaceae and Chrysobalaneae, 

 are zygomorphic; those of the other families are actinomorphic. In some Mimoseae, 

 Crassulaceae, and Styracaceae the petals are connate at the base. Small, incon- 

 spicuous, greenish petals are exhibited by some Agrimoneae, Dryadeae, Saxifragaceae, 

 Crassulaceae, and by many Hamamelidaceae and Rhamnaceae ; but most of the 

 species of the aUiance Crateranthae have brightly-coloured petals. Dusty pollen has 



