634 PART III. — THE CLASSIFICATION OF PLANTS. 



surrounded by an epicalyx formed by the connate stipules of the sepals (Fig. 

 330 C). The stamens are usually indefinite, each whorl consisting of as many 

 or twice as many stamens as there are petals. These flowers are distinguished 

 from those of the Ranunculacese, which they somewhat resemble, by the whorled 

 arrangement of the stamens and by the presence of the hollow receptacle ; 

 for in Eanunculaceous flowers the stamens are arranged spirally and the sepals 

 are quite free. 



Of the genus Potentilla, the Cinquefoil, which has dry fruits and a dry 

 receptacle, many species are common, such as P. anserina, the Silver-weed, 

 reptans, Tormentilla, &nd others : the sub genus Sibbaldia includes the species 

 F. procumbens, which is found on Scottish mountains : the sub-genus Comarum • 

 includes the species P. Co»iarMni,the Marsh Cinquefoil. Fragaria is the Strawberry; 

 the receptacle becomes succulent as the fruit ripens and bears the small achenes 

 on its surface; F. vesca and elatior are found in woods ; F. tirginiana and other 

 North American species are cultivated. In the genus Rubus there is no 

 epicalyx, the ovary contains two ovules, and the fruits are succulent (drupels) ; 

 Rubus Idceus is the Easpberry ; its fruits separate from the dry receptacle when 

 they are ripe : in R. fruticosus, the Blackberry, and R. ccesius, the Dewberry, 

 the upper part of the receptacle separates together with the fruits when ripe. 

 Dryas octopeala, the Mountain Avens (without epicalyx) is a procumbent 

 alpine shrub with an oval long-tailed fruit (resembling that of Clematis Vitalha). 

 An epicalyx is present in most species of Geum : Geum urbanum and rivale 

 (Avens) occur in woods and damp fields ; the long style is hooked. 



Tribe 6. Pomece. Ovaries five (X fewer, contained in the cavity of the 

 receptacle, connate, and adnate to the wall of the receptacle (Fig. 433 D). The 

 spurious fruit is surmounted by the calyx. The individual fruits either become 

 hard and are like small drupes imbedded in the fleshy receptacle, or they have 

 only a thin wall, so that they are m^ re like capsules and seem to be loculiof the 

 whole fruit, as in the apple for instance, where the succulent portion is derived 

 from the receptacle, and the core consists of the fruits enclosing the seeds, 

 which are basal, generally two in each carpel. Stamens indefinite : no epicalyx, 

 Shrubs or trees with deciduous stipules. 



I. With stony fruits. 



In the genus Cotoneaster, the fruits project above the receptacle : in CrataD- 

 gus, the Hawthorn, they are completely enclosed ; C Oxyacautha, the May, and 

 its var. monogyna, the common White Thorn, are common ; other species fr.)m 

 the East and from North America are cultivated : Mespilus, the Medlar, has a 

 large fruit which is surmounted by the five large sepals. 



II. With coriaceous fruits. 



The genus Cydonia, the Quince, has numerous ovules on the ventral suture of 

 each carpel ; the outer layers of cells of the testa are mucilaginous. The genus 

 Pyrus has two basal ovules: P. communis and others are the Pear-trees ; the 

 loculi of the spurious fruit, seen in transverse section, are rounded towards the 

 exterior ; the fruit is not hollowed at the base : the sub genus Malus includes 

 P. Malus and others, the Apple-trees ; the fruit is hollowed at the base, and 

 the loculi, seen in transverse section, are pointed towards the exterior : the sub- 

 genus Sorbus resembles the preceding, but has pinnatifid leaves ; it includes 

 P. Aucuparia, the Mountain Ash or llowan-tree, as also P. domestica, the 



