116 CONVOLVULACEAE 



short-petioled; corolla 5 lines broad; hoods purplish, overtopping the stamen- 

 column. 



Dry slopes, 4000 to 5000 feet : eastern Mohave Desert. East to Arkansas and 

 Texas. June. 



Loc3. — Fountain Canon, Providence Mts., Mary Beal ; Clark Mt., Mum. 



Eefs. — ASCLEPIODORA DECUMBENS Gray, Proc. Am. Acad. 12:66 (1876) ; Jepson, Man. 775 

 (1925). Anantherix decumhens Nutt., Trans. Am. Phil. Soc. n. ser. 5:202 (1837), type loc. hills 

 near the junction of the Kiamesha and Red rivers, Ark., Nuttall. 



CONVOLVULACEAE. Morning-glory Family 



Ours twining or trailing herbs. Leaves simple, alternate, or the plants leafless 

 parasites. Flowers complete and perfect. Sepals 5, distinct or nearly so, imbri- 

 cated, persistent, often unequal. Corolla regular, usually showy, usually open- 

 funnelform or more or less campanulate, entire or shallowly 5-lobed, commonly 

 folded longitudinally and twisted in the bud. Stamens 5, borne on the corolla, in- 

 cluded (exserted in Cressa). Pistil 1; ovary superior, 2 (rarely 1) -celled, with 2 

 ovules (rarely 1) in each cell. Styles 1 or 2. Fruit most frequently a capsule, 1 to 

 4 (or 6) -seeded. Embryo with folded cotyledons; endosperm scanty. The em- 

 bryo of Cuscuta is filamentous and sometimes destitute of cotyledons.- — Species 

 about 1100 in 47 genera, mostly warm regions, all continents. 



Bibliog. — Choisy, J. D., De Convolvulaceis dissertatio tertia (Mem. Soc. Phys. et Hist. Nat. 

 Geneva 9:201-288, t. 1-5, — 1841). Engelmann, Geo., papers on Cuscutineae in Collected Works, 

 59-108 (1887). Brandegee, T. S., Convolvulus occidentalis Gray (Zoe 1:85-80,-1890). Greene, 

 E. L., New species of Convolvulus (Pitt. 3:320-333, — 1898). House, H. D., A new species of 

 Dichondra (Muhl. 1:130-131, — 1906) ; Synopsis of the Californian species of Convolvulus (Muhl. 

 4:49-56,-1908). Heller, A. A., New w"estern plants (Muhl. 8:137-142,-1913). Gray, G. P., 

 Sprayiag for control of Wild Morning Glory, Convolvulus arvensis L., in the fog belt (Cal. Agr. 

 Exp."Sta. Circ. 168:1-7, — 1917). Yuncker, T. G., Revision of the N. Am. and West Indian species 

 of Cuscuta (Univ. HI. Biol. Monog. G--^:1-U1, pis. 1-13,-1921); The genus Cuscuta (Mem. 

 Torr. Club 18:109-330,-1932). Farwell, O. A., Notes on Volvulus (Am. Midland Nat. 12:129- 

 131, — 1930), where many of our species are transferred to Volvulus. Ball, W. S., & Eobbins, 

 W. W., Wild Morning-glory (Mo. Bull. Cal. Dept. Agr. 24:192-194, col. pi.— 1935). 



Ovary deeply 2-lobed ; styles 2, distinct or only slightly united at base ; corolla-lobes imbricate in 



the bud; creeping herbs 1. Dichondea. 



Ovary entire. 



Style 1, entire or cleft at the apex only; corolla plicate and twisted in the bud; prostrate or 

 twining herbs, one species woody. 



Stigma filiform or ovate; corolla-limb pale purple to white 2. Convolvulus. 



Stigma capitate; corolla limb dark blue or rose 3. Ipomoea. 



Styles 2, distinct ; corolla-lobes imbricate in the bud. 



Erect non-twining leafy herb 4. Cbessa. 



Leafless twining parasites 5. Cuscuta. 



1. DICHONDRA Forst. 



Perennial herbs (siiggesting acaulescent violets) . Stems slender, creeping, with 

 reniform leaves and very small obscure solitary flowers at or just below the surface 

 of the ground on short axillary peduncles. Calyx deeply 5-parted. Corolla 5-cleft, 

 the lobes imbricated in the bud. Stamens short. Ovary deeplj^ 2-lobed, separating 

 when ripe into 2 one-seeded utricles which sometimes break open irregularh^ Styles 

 2, in ours united at base or apparently distinct. — Species 4 or 5, temperate and 

 tropical regions, all continents. (Greek, di, double, and chondra, grain, on account 

 of the deeply parted and twin fruit.) 



1. D. repens Forst. Stems pubescent to tawny hirsute, rooting freely; leaf- 

 blades entire or retiise, green and appressed silky pubescent below, ^^ to l^/^ inches 

 wide, on petioles about twice their lengtli; calyx in flower shallowly lobed, hairy, 

 but accrescent, and in fruit deeply cleft, glabrate and somewhat thinnish; corolla 



