THE POLYPETALOUS ORDERS. 381 



usually without stipules. Flowers perfect. Calyx of three to 

 nine sepals, imbricated, in one to several rows, often colored. 

 Petals as many as the sepals and in two sets, or twice as many, 

 with a pore, spur, or glandular appendage at the base. Stamens 

 equal in number to the petals and opposite them, or rarely more 

 numerous ; anthers extrorse, the cells commonly opening by an 

 uplifted valve. Carpel solitary, often gibbous or oblique, forming 

 a one-celled pod or berry in fruit. Seeds sometimes with an aril : 

 embryo (often minute) surrounded with fleshy or horny albumen. 

 Ex. The Barberry (Fig. 503-511), the sharp spines of which 

 are transformed leaves (296) ; the Mahonias are Barberries with 

 pinnated leaves. Leontice (Caulophyllum) thalictroides, the Blue 

 Cohosh, is remarkable for its evanescent pericarp (559), and the 

 consequent naked seeds, which resemble drupes. Podophyllum 

 (the Mandrake) presents an exception to the ordinal character, 

 having somewhat numerous stamens, with anthers which do not 

 open by valves; but the latter anomaly is also found in Nandina. 

 The order is remarkable for this valvular dehiscence of the an- 

 thers, and for the situation of both the stamens and petals opposite 

 the sepals. But this latter peculiarity is doubtless owing to the 

 production of two or three whorls both of the petals and the 

 stamens, which does away with the anomaly. The aestivation 

 in Berberis clearly shows this to be the case. The fruit is inno- 

 cent or eatable ; the roots and also the herbage sometimes poi- 

 sonous. 



712. Ord, Cabombaces (the Water-shield Family). Aquatic herbs, 

 with the floating leaves entire and centrally peltate, involute in ver- 

 nation ; the submersed foliage sometimes dissected. Flowers sol- 

 itary, rather small. Calyx of three or four sepals, colored inside, 

 persistent. Corolla of as many persistent petals. Stamens six to 

 thirty-six, with slender filaments and innate anthers. Carpels two 

 to eighteen, indehiscent, with two or few (anatropous) ovules in 

 each, inserted on the dorsal suture ! Seeds pendulous, with a mi- 

 nute embryo inclosed in a membranous bag (the persistent em- 

 bryo-sac, 575), which is half immersed in the albumen at the ex- 

 tremity next the hilum. Ex. Brasenia, the Water-shield (Fig. 

 512), and Cabomba, compose this very small order; the appar- 

 ently single species of the former grows both in the United States 

 and in New Holland. They are only reduced forms of Nymphse- 

 acese. 



