SECT. II 



PHANEROGAMIA 



597 



times straggling climbers, with xmequally pinnate leaves, the large stipules of 

 which are adherent to the base of the leaf-stalk, and brightly coloured, con- 

 spicuous flowers. Sepals, inserted on the margin of the receptacle, leafy and 

 pinnately divided (cf. Fig. 511). The double flowers result from the petaloid 

 development of many of the stamens. Agrimonia and Hagenia abyssinica have a 

 dry cup-shaped receptacle. Hagenia is a dioecious tree with unequally pinnate 

 leaves, the adherent stipules of which render the petiole winged and channelled. 

 Inflorescence a copiously branched panicle. Each flower has two bracteoles and an 

 epicalyx. The flowers are unisexual by suppression of the male and female organs 

 respectively. The corolla later falls off and the sepals become inrolled, while the 

 epicalyx enlarges. The two free carpels have each a single ovule. Fruit one-seeded 

 (Figs. 624, 625). Alchemilla has no petals ; the lack of a conspicuous corolla may 

 perhaps stand in relation to the apogamous development of the embryo ( lla ) 



Wi\w 



^PF 



Via. 626. Kulin.t ulaeux. Klnwcrin^ branch and fniits. (i uat. size.) 



(Fig. 621, 2). Sanguisorba ojficinalis has polygamous flowers (cf. p. 541), without 

 epicalyx or corolla, aggregated in heads. Flowers tetramerous with 1-2 carpels 

 (Fig. 620 Z>). 



(d) Potentilleac. Floral receptacle plate-shaped, flat or convex and bearing 

 numerous free carpels which develop into nutlets, drupes, or berries. Each carpel 

 with one ovule. Epicalyx often present. Potentilla with a number of British 

 species (Fig. 621, 1). Geum and Dryas have hairy carpels which elongate in fruit 

 and are distributed by the wind. The latter genus includes arctic and alpine 

 forms. Fragraria, Strawberry, with small achenes situated on the succulent, 

 enlarged, floral receptacle. Ifubus, Blackberry, has numerous species, mostly 

 scrambling shrubs with recurved prickles. Leaves trifoliate. Ji. idaeus, the 

 Raspberry, is one of the few species which are not straggling climbers (Fig. 626). The 

 small drupes are closely crowded on the convex receptacle, only slightly connected 

 with one another. The withered style is for a long time visible on the partial fruits. 

 11. fruticosus. 



