262 POLYPETALOUS ORDEKS. 



calyx upon which the stamens are inserted ; pi, the pistil ; /, the 2-celled anther 

 with the upper part of the filament ; o, the ovary cut vertically ; s, fruit ; b, verti- 

 cal section of a carpel ; m, horizontal section of the exalbuminous seed ; n, the em 

 bryo^ which fills the entire seed. 



446. CALYCANTHACEiE, the Colycantlius Tribe. — Shrubs with 

 quadrangular stems (which exhibit when old 4 axes of growth 

 surrounding the old wood). Leaves opposite, without stipules. 

 Sepals and petals confounded. Stamens numerous ; anthers 

 adnate, extrorse. Ovaries indefinite, simple, 1-celled. Fruit 

 consisting of achcenia, inclosed in the fleshy tube of the calyx. 

 Seeds Avitliout albumen ; embryo straight. 



Genus. — Calycanthus. 



447. Myrtace^, tJie Myrtle Tribe. — Trees or shrubs. Leaves 

 opposite, entire, and dotted, without stipules. Calyx adherent 

 to the ovary ; limb 4 or 5 cleft. Petals 4 or 5, or wanting. 

 Sta?ne7is indefinite ; filaments long ; anthers ovate. Ovary 

 1-6-celled ; ovules pendulous or erect. Seeds numerous, with- 

 out albumen ; embryo straight or curved. 



a. Properties : these plants abound in an aromatic volatile oil and an astringent 

 piinciple. 

 Genus. — Myrtus, Punica. 



448. MELASTOMACEiE, the Melastoina Tribe. — Trees^ shrubs^ or 

 herbs. Leaves opposite, ribbed. Flowers showy. Sepals 4, 5, 

 or 6, more or less united. Stamens as many, or twice as many 

 as the petals ; anthers opening by pores, inflexed in sestivation. 

 Ovary adherent to the tube of the calyx. Fruit capsular or 

 Buccident. Seeds attached to central placentae, exalbuminous; 

 embryo straight or curved. 



a. Properties : the berries of Melastoma are edible. 

 Genus. — Rhexia, Melastoma 



449. Lythrace^, tlie Loosestrife Tribe. — Herbs and shrubs. 

 Leaves opposite, entire. Calyx tubular, lobed ; sometimes the 

 lobes have intermediate lobes or teeth. Petals inserted into 

 the calyx, alternate with its primary lobes, deciduous. Sta- 

 mens inserted into the tube of the calyx below the petals. 

 Ovary 2-4-celled ; styles united into one. Fruit a capsule. 

 Seeds numerous, exalbuminous, attached to a central placenta ; 

 embryo straight. 



o. Properties : astringent useful for dyeing 

 Geneea. — Ly thrum, Cuphea, Ammannia, Decodon. 



450. Khizophorace^, the Mangrove Tribe. — Trees or shrubs. 

 Leaves simple, opposite, with inter-petiolary stipules. Calyx 

 adherent, 4-12-lobed. Petals alternate with the lobes of the 

 calyx. Stamens twice or thrice as many as the petals with 

 which they are inserted. Ovary 2-celled ; ovules 2 in each cell. 



