392 



EXOGENOUS OR DICOTYLEDONOUS PLANTS. 



many, as the petals, sometimes reduced to two or three. Styles 

 two to five, stigmatose down the inside. Ovary mostly one-celled, 

 with a central or basilar placenta. Capsule two to five-valved, or 

 opening only at the apex with twice as many valves as stigmas. 

 Embryo peripheric, curved or coiled around the outside of mealy 

 albumen. There are five principal suborders, viz. : 



728. Subord, SileneSB (the proper Pink Family) : in which the 

 sepals are united into a tube, and the petals (mostly convolute in 

 aestivation) and stamens are inserted on the stipe of the ovary, the 

 former with long claws ; and there are no stipules. Ex. Silene, 

 Dianthus (the Pink, Carnation). 



729. Subord, Alsinea; (the Chickweed Family) ; in which there are 



no stipules, the ovary 

 is sessile, the sepals 



f/// r,:m/Ti ^417 and petals (imbricat- 



ed in aestivation) are 

 nearly or quite dis- 

 tinct ; the petals des- 

 titute of claws ; and 

 the stamens are in- 

 serted into the margin 

 of a small hypogynous 

 disk, which, however, 

 occasionally coheres 

 with the base of the ca- 

 lyx, and becomes peri- 

 gynous. Ex. Stel- 

 laria, Arenaria, &c. 

 (Chickweeds). Some 

 are ornamental; oth- 

 ers, such as the common Chickweed, are insignificant weeds. 



730. Subord, IllecebreSB (the Knotwort Family) ; differing from the 

 last in having scarious stipules ; the sepals often united below ; the 

 petals often wanting or rudimentary ; the stamens manifestly peri- 

 gynous, and the fruit more commonly a one-seeded utricle. Ex. 

 Paronychia and Anychia, Spergula has conspicuous petals, and 

 many-seeded capsules ; and so differs from Alsinea? only in its 

 stipules. Insignificant weeds of no economical account. 



FIG. 557. Arenaria lateri flora. 558. A magnified flower. 559. Magnified section of a seed, 

 showing the embryo coiled into a ring around the albumen. 560. Vertical section of a pistil of 

 Spergularia. 



