EANUNCULACE.E. 



353 



able, and increases by additions on the inside. The epidermis is furnished 

 with stomata (^[ 50). The leaves are reticulated (^[ 143), usually 

 articulated to the stem. The flowers are formed upon a quinary 

 or quaternary type, and have stamens and pistils. The ovules are 

 either enclosed in a pericarp, and fertilized by the application of the 

 pollen to the stigma, or they are naked, and fertilized by the direct 

 action of the pollen. The embryo has two or more opposite cotyle- 

 dons, and is exorhizal in germination (^[ 629). 



Subclass 1 THALAMIFLOE^;.* 



737. Calyx and corolla present; petals distinct,! inserted into the thala- 

 mus or receptacle ; stamens hypogynous. This includes the hypogynous 

 polypetalous orders of Jussieu, and a diclinous order (Menispermaceae). 



738. Order 1. Ranuncuiacece, the Crowfoot Family. (Polypetalce 

 Hypogynce.) Sepals 3-6, frequently 5, deciduous 



(fig. 556 c). Petals 5-15 (fig. 556 p e), rarely 

 abortive, sometimes anomalous in form (figs. 

 284 p, 285), occasionally with scales at the 

 base (fig. 555 a). Stamens usually indefinite, 

 hypogynous (fig. 556 e) ; anthers adnate (figs. 

 558, 559) ; carpels numerous, 1 -celled (fig. 

 556 p i), distinct, or united into a single many- 

 celled pistil ; ovary containing one anatropal 

 ovule (figs. 492, 560 g), or several united to 



561 560 559 556 558 



the inner edge. Fruit various, either dry achamia (figs. 463, 561), 



* Thalamu.i, receptacle, and_/7o.s, flower. 



t Sometimes the petals are abortive, and it is then difficult to determine whether the plant 

 belongs to this subclass or to Monochlamydese. 



Figs. 556 561. Exhibit the organs of fructification of Ranunculus acris, to illustrate the 

 natural order Ranunculacese. 



Fig. 556. Flower cut vertically, c, Calyx, pe, Petals. , Stamens, pi, Pistil composed of 

 several carpels on an elongated receptacle or axis. 



Fig. 557. Diagram of the flower, showing 5 imbricated sepals, 5 petals alternating with the 

 sepals, indefinite stamens in several whorls, multiples of the petals, and numerous carpels or 

 achsenia in the centre. 



Fig. 558. Adnate anther seen on the outer side. The anther is in this instance extrorse. In 

 Pawnia and other Ranunculaceoe it is introrse. 



Fig. 559. Adnate anther viewed on the inside. 



Fig. 560. Vertical section of the ovary, o, showing the ovule, g. s, Stigma. 



Fig. 561. Fruit or achamium cut vertically. /, Pericarp, t, Spermoderm or integument of the 

 anatropal seed, p, Perisperm or albumen, between fleshy and horny, e, Minute embryo. 



2 A 



