570 Order 93.— CONVOLVULACEjE. 



branches ; cor. tube thrice longer than calyx, segra. oval-oblong, erect-spreading ; 

 !=tam. barely exserted. — © Along rivers, S. Car., Ga., Ala. A splendid herb, 2 

 to 4f high, its plume-like form closely beset with delicate fringe-like leaves and 

 bearing at top a long (If) thyrse of scarlet red flowers. Cor. 15" long. Jl. 

 (I pomopsis, Mx. Cantua, Juss.). — A more slender form found in Fla. is G. Florid- 

 ana Don. 



2 G. tricolor Benth. Tricolored Gilia. St. erect, nearly smooth ; lvs. twice 

 or tbrico pinuatifid, with narrow, linear segments; cymes paniculate, 3 to 6-fiow- 

 ered; cor. tricolored, 2 or 3 times longer than the calyx, tube very short. — (I) An 

 elegant little garden plant, from California, If high. Fig. numerous, limb pale 

 lilac-blue, throat purple and tube yellow. % 



4. DIAPEN'SIA, L. Calyx of 5 oval imbricated sepals, closely sub- 

 tended by imbricated bracts; corolla campanulate, imbricated in the 

 bud ; filaments 5, flat, arising from the sinuses of the corolla ; anther- 

 cells diverging at base and the dehiscence transverse ; capsule papery, 

 enveloped in the persistent calyx, 3-cclled, many-seeded. — Prostrate 

 undershrubs with densely imbricated, linear lvs. and solitary terminal fls. 



§ 1. Diapensia proper. Anthers without awns. Flowers pedicellate No. 1 



J 2. Pyxidantiikka. Anthers with the lower valve awned. Flowers sessile No. 2 



1 D. Lapponica L. Casspitous ; lvs. dense, spatulate, fleshy, evergreen, obtuse 

 and entire; fls. pedunculated. — U A little, leafy plant, 2 — 3' high, growing on 

 tho summits of the White Mts. in N. Hampshire, forming dense tufts among the 

 rocks. Leaves crowded, pale beneath, fleshy, 5 — 8" by r" with a revolute margin, 

 clasping base, and broadly obtuse point. Fls. on slender (1' long) terminal, soli- 

 tary peduncles. Calyx of 5, obtuse leaves, longer than tho leafy bracts at its 

 base. Corolla white, with 5, flat segments. July. 



2 D. barbulata Ell. Branches short, ascending; lvs. lance-cuneiform, acute, 

 pubescent at base ; fls. terminal, sessilo ; lower valve of the anther beaked or 

 awned at base. — A prostrate, creeping plant, abundant in pine barrens, N. J. to 

 Car., forming dense beds. Stems 3 — 6' long, subhispid. Leaves 1 — 2" by \ — 1". 

 Flowers white, 3" diam. Sepals denticulate, as long as the corolla tube. May, 

 Jiu — The beak of the anther is variable, sometimes reduced to an acute point. 

 (Pyxidanthera barbulata Mx. D. cuneifolia Ph.) 



Order XCIII. CONVOLVULACE^E. Bindweeds. 



Chiefly twining or trailing herbs, sometimes parisitic, sometimes shrubby. Leaves 

 (or scales when leafless) alternate. Flowers regular, pentamerous and 5-androus. 

 Sepals imbricated. Corolla monopetalous, 5-plaited or lobed, convolute in bud. 



Ovary freo, 2 (rarely 3)-celled or falsely 4-celled, or of 2 distinct, 1-ovuled pistils. 



Capsule 2 to G-seeded. Embryo large, coiled in mucilaginous albumen. (Illustr. in 

 flg. 41), 50, 303, 321, 338, 455, 456.) 



Geneva 50, species 700, abundant in tropical climates, rare in cold. 



Properties. — The roots of many species abound in an acrid, milky juice which is strongly 

 purgative. Jalap of the shops is the product of the root of Exogoniutn purga, of Mexico, and of 

 oilier species ; scummony, of Convolvulus scammonia, native of Levant. The drastic qualities 

 <>f both depend upon the presence of a peculiar resin. Other species have large farinaceous 

 tubers. The Sweet Potato, a valuable article of food, is tho product of C. Batatas, native at the 

 South. 



TRIBES AND GEXERA. 

 III. CUSCUTINEiE. Leafless, parasitic, twining. Embryo without cotyledons... Cuscut a.. 10 

 IL DICHONDRE^E. Leafy. Ova. 2, distinct, with 2 distinct styles. South.. .Dichondka. D 

 I. CONVOLVULEJ3. Leafy. Ovary 1. Capsule dehiscent. Cotyledons leafy, (a) 



a Ovary 2-celled. Styles 2. Pedunclo longer than the leaves Styi.is.ma. 8 



a Ovary 2-cclled. Styles united into one. (b) 



b Calyx enveloped in 2 large bracts Calystegium. 7 



b Calyx nuked. — Stamens exserted. Tube of the corolla slender Calynyction. 6 



— Stamens included — Stigmas 2, linear Convolvulus. 5 



— Stigma capitate Ii-omjm. 4 



