SlO Order 93.— CONVOLVULACE^. 



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

 stam. barely ei-serted. — @ 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 Beuth. Teicolored Gili.i. St. erect, nearly smooth ; -Ivs. twice 

 or thrice pinnatifid, with narrow, linear segments; cymes paniculate, 3' to 6-flow- 

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

 elegant httle garden plant, from Cahfomia, If high. Fls. numerous, limb palo 

 lUac-blue, throat purple and tube yellow, j^ 



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

 tended by imbricated bracte; corolla campanulate, imbricated in the 

 bud ; filaments 6, 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-celled, many-seeded. — Prostrate 

 undershrubs with densely imbricated, linear Ivs. and solitary terminal flp. 



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



§2. Pyxidantueea. Anthers with the lower valve awned. Flowers sessile No. 'i 



1 D. Lapponica L. Csspitous ; Ivs. dense, spatulate, fleshy, evergreen, obtuse 

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

 the summits of the White Mts. in N. Hampshire, forming dense tufls among tlje 

 rocks. Leaves crowded, pale beneath, fleshy, 5 — 8" by 1'' 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 the leafy bracts at its 

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



2 D. barbul^ta Ell. Branches short, ascending; Iva. lance-cuneiform, acute, 

 pubescent at base; fls. terminal, sessile; 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 -J — 1". 

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

 Jn. — The beak of the anther is variable, sometimes reduced to an acute poioL 

 (Pyxidanthera barbulata Mx. D. cuneifolia Ph.) 



Order XCIII. CONVOLVULACE^. Bindweeds. 



Chiefly twining or trailing heris, 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 free, 2 (rarely 3)-celled or falsely 4-ceUed, or of 2 distinct, 1-ovuled pistila 

 Capsule 2 to 6-seeded. Embrj-o largo, coiled in mucilaginous albumen. (Illustr. in 

 fig. 49, 56, 303, 321, 338, 455, 456.) 



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



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

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

 other species ; scammony, of Convolvulus scamnionia, native of Levant. The drastic qualities 

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

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

 , South. 



TRIBES AXD GENERA, 

 in. CUSCUTINEjE. Leafless, parasitic, twining. Embryo without cotyledons... Cuscuta. 10 

 II. DICHOSDKEJ!. Leafy. Ova. 2, distinct, with 2 distinct styles. South... Diciiosdea. 9 

 I. CONVOLVULEjE. Lea'fy. Ovary 1. Capsule dehiscent. Cotyledons leafy, (a) 



a Ovary 2-celled. Styles 2. Peduncle longer than the leaves Stylis.ma. S 



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



b Calyx enveloped in 2 large bracts. Caltstegittm. 7 



b Calyx naked. — Stamens exserted. Tube of tho corolla slender Caltktction. 6 



—Stamens Included. — Stigmas 2, linear Convoltulub. t* 



—Stigma capitate , Ipom^a. 4 



