666 CLT. CONVOLVULACE^. 



Corolla monopeialous, hypogynous, isostemonous, regular, aestivation contorted. 



Stamens 5, inserted at the bottom of the corolla-tube. Ovary of 4 \-2-ovuled cells. 



Ovules collateral, erect, anatropous. Capsule with valves detaching from the septum, 



or a BERRY. Embryo curved; albumen mucilaginous; cotyledons folded; radicle 



inferior. 



Herbaceous, sub-woody or woody plants. Stem generally climbing, ra.rely 



erect, juice usually milky. Leaves alternate, exstipulate. Flowers 5 , regular ; 



peduncles axillary or terminal, simple or trichotomous, usually bibracteolate ; bracts 

 sometimes close together, enveloping the flower. Calyx of 5 sepals, usually free, 

 persistent. Corolla hypogynous, monopetalous, campanulate or infundibuliform 

 or sometimes hypocrateriform, limb 6-fid or forming 6 folds, aestivation generally 

 contorted. Stamens 5, inserted at the bottom of the corolla-tube, alternate with its 

 lobes ; filaments usually dilated below, filiform above ; anthers introrse, 2-celled, de- 

 hiscence longitudinal. Ovary sometimes girt by a disk, with 2-3-4 1-2-OYuled 

 cells, or 1-celled and 1-ovuled by atrophy of the septum ; style terminal, simple or 

 2-partite; ovules solitary or collateral, erect, anatropous. Fruit either capsular, 

 1-4-celled, valves separating from the placentiferous column at its base ; or fleshy, 

 indehiscent. Seeds erect ; testa sometimes very villous ; albumen mucilaginous, 

 scanty. Embryo more or less curved ; cotyledons foliaceous, folded or crumpled ; 

 radicle near the hilum, inferior. 



[Arrangement of Gonvolvulacece :— 



Tribe I. AEGTREiEa;.— Fruit indehiscent, coriaceous or sub-baccate. Carpels connate ; 

 style simple. Embryo with distinct cotyledons. JMvea, Argyreia, &c. 



Tribe II. Convoi.vulej!. — Fruit capsular. Carpels connate ; style simple. Embryo with 

 distinct cotyledons. QuamocUt, Batatas, Pharbitis, Ipomma, Jacquemontia, Convolvulus, Ardseia, 

 Parana, JSvolvulus, &c. 



Tribe III. Dichondrbj!. — Fruit of distinct dry carpels, each with one style. Embryo 

 with distinct cotyledons. See DiCHONDREiE, p. 667. 



Tribe IV. Cqscdteji.— Fruit capsular, often transversely dehiscing. Carpels connate ; 

 styles 2, rarely connate. Embryo spiral, without distinct cotyledons. See CnscuTEJ), p. 668. 



Tribe V. Erycibe^, — Fruit baccate. Carpels connate into a 1-celled ovary with a sub- 

 sessile 6-lobed stigma. Embryo with distinct cotyledons. Hrycibe."] 



Convolmdacece are near Cuscutem and Dichondrea (see these families). They approach Polemoniacea 

 in the insertion, isostemony and aestivation of the corolla, structure of the ovary, anatropy and position 

 of the ovules, capsular fruit, alternate leaves, and often climhing stem ; hut in Polemoniacem the ovary 

 has three many-ovuled cells, the capsule has semi-septiferous valves, the emhryo is straight and axile, 

 and the fleshy albumen abundant. There is a certain analogy between Convolmtlaceee and Cordiacea in 

 the form and sestivation of the corolla, the 2-4-celled ovary, bifid style and anatropous ovules; but in 

 Cordiaceee the radicle is superior, the straight embryo exalbuminous, and the cotyledons are folded longi- 

 tudinally. The erect species approach Solaneee in the insertion, isostemony, aestivation and form of 

 the corolla, in the 2-celled ovary, capsular or berried fruit, curved embryo, inferior radicle, and alternate 

 leaves ; but in Solaneee the ovule is campylotropous, the albumen copious, and the radicle is distant from 

 the hilum. There is also a distant connection between Convohidacete and Hydrophyllea (which see). 



