ORDER 21. CARYOPHYLLACE^S. 253 



ORDER XX. ELATINACE^E. WATER PEPPERS. 



Herbs small, annual, with opposite leaves and membranous stipules. Fls. minuto 

 axillary. Sepals 2 5, distinct or slightly coherent at base, persistent. Petals hy- 

 pogynous, as many as the sepals. Sta. equal in number to, or twice as many as 

 the petals. Anth. introrse. Ova. 2 G-celled. Stigmas 2 5, capitate ; placenta in 

 the axis. Fr. capsular. Seeds numerous, exalbuminous. 



Genera C, species 22, found in every part of the globe, growing in marshes. The following is 

 our only northern genus. 



ELATINE, L. (Gr. e/Urr?/, fir ; from the resemblance of the slender 

 leaves of some species.) Fls. 2 4-merous. Stigmas sessile, minute. 



B. Americana Arn. MUD PURSLANE. St. diffuse, procumbent, striate, rooting 

 from the joints, with assurgcnt branches ; Ivs. lance-oval or obovate, obtuse, 

 entire ; sty. ; sep., pet, sta., stig. 2 3, as well as the cells and valves of tho 

 capsule; stip. very minute. A little mud plant, on the borders of ponds and 

 rivers, IT. S. Fls. axillary, sessile, solitary. Cor. minute, closed. Jl.- Sept. 

 (Crypta minima Nutt. Peplys Americana Ph.) 



ORDER XXI. CARYOPHYLLACE^E. PINKWORTS. 



Herbs with swollen joints, opposite, entire leaves, and regular flowers. Sepals 

 4 or 5, persistent, distinct, or cohering into a tube. Petals 4 or 5, unguiculate or 

 not, bifid or entire, mostly removed from the calyx by a short internode of the torus, 

 sometimes wanting. Stamens distinct, twice as many as the petals, rarely an equal 

 number or fewer. Ovary often stipitate ; styles 2 5, Btigmatous the whole length 

 of the inner surface. Fr. a 1 -celled capsule (or imperfectly 2 5 celled), opening at 

 the top, or loculicidal. Sds. numerous; embryo curved around the albumen. (Seo 

 Figs. 70, 209, 258, 296, 299, 300, 313, 392.) 



The Pinkworts as constituted by Emlleicherand others, and above characterized, comprehends 

 four Suborders, and in the aggregate SS genera and 1180 species. They are in general destitute 

 of active properties. A few of them are valued as highly ornamental in cultivation, but tho 

 greater part are insignificant weeds abounding in waste sandy tracts throughout the temperate 

 zones. 



Leaves furnished with dry, membranous stipules. SUBORDER II. (^) 



Exstipulate. Capsule 1-celled, 3 00-seeded. Petals rarely absent. SUBORDER !.() 

 Capsule 1-celled, 1-sceded. Petals none. SUBORDER III. (h) 

 Capsule completely 3-cclled. Petals none. SUBORDER IV. (k) 



* Sepals united into a tube. Petals long-clawed. Ovary 6tiped. TRIBE 1. (a) 



* Sepals distinct or nearly so. Petals subscssile. Ovary sessile. TRIBE 2. (b) 

 T Styles or stig. 3 to 5. Capsule 1 -celled, 00-sceded. TRIBE 8. (e) 



^ Styles 2 or united into 1. Utricle 1-seeded. TRIBE 4. (f ) 



SUBORDER I. CARYOPHYLLINEJE. 



al. SILENEuE. Calyx with scale-like bractlets at base. Styles 2 DiAKTnrs. 1 



Calyx bractless. Styles 2. Capsule 4-toothed when open. SAPON ARIA. 2 



Styles 3. Capsule 6-toothed when open . SILENK. 3 



Styles 5. Caps. 10-toothed. . . AGROSTEMMA, 4. .I/rcuxis. 5 

 b 2. ALSINEjE. -Petals 2-parted (sometimes wanting in No. 7.) (c) 



c Styles 5. Capsule opening at tho top by 10 teeth CERASTIUM. <? 



c Styles 3. Capsule opening deeply by 6 half- valves.. .STILLARIA. T 

 Petals undivided (sometimes wanting in No. 10.) (d) 



d Valves of the capsule 3, each 2-toothed. Styles 3 ARENARIA. 8 



d Valves, &c., entire. Styles 3, always fewer than sepals ALSIJTE. 9 



Styles 4 or 5, always as many as sepals.. SAGINA. 10 



Styles 8 & 5. Disk large, 10-lobed.HoNKKNYA. 11 



SUBORDER II. ILLECEBRINE^E. 



e 8. SPEEGULEJE. Styles 5. Petals white. Lvs. linear, whorled Si ERCULA. 12 



Styles 3 and 5. Petals red. Lvs. linear, opposite SPEROULAP.IA. 13 



Styles 3 in all the flowers. Stipules ovate. Lvs. in 4's.PoLTCARPOX. 14 

 Slip, inultifltl. Lvs. opp. . . STIPULICIDA. 15 



