_Adonis_, _Pæonia_.--The perianth of the Ranunculaceæ is considered by Prantl to be usually petaloid.--The nectaries arise in the Ranunculaceæ (1) on normal stamens (_Clematis_ sect. _Viorna_), (2) on the honey-leaves (this is generally the case), and (3) on the carpels (_Caltha_ and the majority of _Trollius_-species).--As the result of his researches upon the Ranunculaceæ, Prantl does not agree with the view advanced by Drude (Schenk, _Hand. d. Bot._ iii.) that the petals in general have proceeded from the metamorphosis of the stamens (_K_)]. [Illustration: FIG. 373.--Ovaries in longitudinal section: _v_ the ventral suture; _d_ the dorsal suture: _A_, _B Clematis_; _C Ranunculus_; _D Myosurus_.] The most primitive form of fruit is undoubtedly the pod formed by one carpel, on the edges of which (along the ventral suture) two rows of ovules are situated: Pæonieæ, Helleboreæ, Delphinieæ (Fig. 379). In a great many genera the number of ovules has been limited to _one_ perfect one, which is placed in the central plane under the united leaf-edges, and sometimes also some barren ovules above it (Fig. 373). The fruitlets in this case become achenes, and are present in much larger numbers than when there are follicles. [Illustration: FIG. 374.--_Helleborus niger_: _A_ flower; _B_ receptacle; _pet_ petals (honey-leaves); _pi_ stamens and carpels; _C_ seed; _D_ anther (cross section); _alb_ endosperm.] [Illustration: FIG. 375.--_Caltha palustris_: fruit.] The following have FOLLICLES: _Pæonieæ_, _Helleboreæ_ (except _Actæa_) and _Delphinieæ_; ACHENES: _Ranunculeæ_, _Anemoneæ_ and _Clematideæ_. =A. Follicles= (Figs. 375, 379), with many ovules, situated in two rows along the ventral suture. ~_Actæa_ has berries, _Nigella_ has capsules of several loculi.~ =1.= PÆONIEÆ, PEONY GROUP. This has regular, acyclic flowers with a normal, most frequently 5-leaved, imbricate calyx; large, coloured petals, and introrse anthers. Slightly perigynous. Surrounding the base of the carpels a ring-like swelling of the receptacle (“disc”) is present, which is largest in _P. moutan_. The follicles are more or less fleshy or leathery. Mostly herbs, with pinnatisect or decompound leaves and large, solitary flowers; a gradual transition may be traced from the foliage-leaves to the petals. _Pæonia; Hydrastis._ [Illustration: FIG. 376.--_Aquilegia vulgaris._] [Illustration: FIG. 377.--_Caltha palustris_ (nat. size).] [Illustration: FIG. 378.--_Nigella_: _A_, _B_ fruit of _N. damascena_, entire, and cut transversely. _C_ Petal (honey-leaf) of _N. arvensis_. _D_ Petal of _N. damascena_.]