BOTANY. 143 



unisexual flowers sometimes none, or often simple (calyx), arinate to the 

 ovary in the fertile flowers, three- to five-cleft in the sterile flowers ; in the 

 perfect flowers double, viz. calyx adnate to the ovary ; the limb entire or 

 denticulate, or often obsolete. Corolla of three to four or eight petals, 

 either distinct, or more or less coherent in a tube, inserted into the 

 epigynous disk; jEstivation valvate. Stamens equal in number with the 

 petals and opposite them, or as many as the segments of the calyx, and 

 inserted upon them when the perianth is simple. Ovary one-celled, with a 

 single suspended ovule ; style simple, or none. Fruit baccate, one-celled, 

 one-seeded. Seed anatropous ; the membranous testa often adhering to the 

 walls of the fruit. Embryo in a superficial cavity of the fleshy albumen ; 

 radicle clavate, often exserted ; cotyledons obtuse, sometimes connate. 

 Parasitical, half-shrubby, evergreen plants, with dichotomous stems. Leaves 

 mostly opposite, fleshy or coriaceous, almost veinless ; sometimes reduced 

 to scales or entirely wanting. Stipules none. Flowers unisexual and 

 small (whitish or greenish yellow), or perfect and very showy. 



Many of the plants are tropical, and hang from the trunks and branches 

 of trees ; others occur in temperate regions. Lindley gives 23 genera and 

 412 species, of which two genera, Viscum and* Arceuthobium, with thi-ee 

 species, are North American. Viscum album is the mistletoe of English 

 writers. 



Sub-class 3. CalycißorcB. 



In this division are included the polypetalous orders of Jussieu, in which 

 the stamens are not hypogynous, as well as some diclinous orders. A calyx 

 and corolla are present ; in other words, the plants are dichlamydeous, the 

 petals are distinct, and the stamens are attached to the c»ilyx, being thus 

 more or less perigynous. This sub-class, along with Thalamiflorte, com- 

 prises the Dialypetalffi of Endlicher. De Candolle included in this division 

 gamopetalous plants, in which the ovary is inferior. 



Ordkr 123. CoRNACE.f:, the Dogwood Family. Calix, four-lobed. Petals 

 four, oblong, broad at the base, regular, inserted into the upper part of the 

 calycine tube ; aestivation valvate. Stamens four, inserted along with the 

 ))etals, and alternate with them ; anthers dithecal. Ovary adherent to the 

 tube of the calyx, two-celled, crowned by a disk ; ovules solitary, pendulous, 

 anatropal ; style filiform ; stigma simple. Fruit fleshy, crowned by the 

 limb of the calyx, two-celled, rarely one-celled by abortion; endocarp bony. 

 Seeds solitary, pendulous ; embryo straight, long in the axis of fleshy 

 albumen ; radicle superior, shorter than the oblong cotyledons. Trees, 

 shrubs, or herbs, with opposite, very rarely alternate, exstipulate leaves, and 

 capitate, umbellate, or corymbose flowers. They inhabit the temperate 

 climates of Europe, Asia, and America. The most prominent North 

 American species of this family is Cornus florida, or the Dog wood, a showy 

 member of our forests. Lindley enumerates nine genera and forty species, 

 of which but one genus (Cornus), with eleven species, belongs to North 

 America. 



143 



