CONVOLyXILACE^. (CONVOLVULUS FAMILY.) 377 



2-seeded. — Low and small herbs or suffrntescent plants, mostly diffuse, never 

 twining (hence the name, from evolvo, to unroll, in contrast with Convolvulus). 

 1. S. argtoteus, Pursh. Many-stemmed from a somewhat woody base, 

 dwarf, silky- villous all over ; leaves crowded, broadly lanceolate, sessile, or the 

 lower oblong-spatulate and short-petioled, about ^' long ; flowers almost sessile 

 in the axils; corolla purple, 3" broad. — Potx)si lead-mines, Missouri, probably 

 also on the Illinois side of the Mississippi : common westward. 



7. DICH6NDBA, Forst. Dichondra. 



Calyx 5-parted. Corolla broadly bell-shaped, 5-cleft. Stamens included. 

 Styles, ovaries, and the utricular 1 -2-seeded pods 2, distinct. Stigmas thick. 

 — Small and creeping perennial herbs, soft-pubescent, with kidney-shaped 

 entire leaves, and axillary 1-flowered bractless peduncles. Corolla small, yel- 

 lowish or white. (Name composed of Sif, double, and j^ovSpos, roundish mass; 

 from the fruit.) 



1. D. ripens, Forst. : var. Carolin6nsis, Choisy. Leaves round-kid- 

 ney-shaped, pubescent, green both sides; corolla not exceeding the calyx (1"- 

 Ij" long). (D. Carolinensis, Michx.) — Moist ground, Virginia, near Norfolk, 

 and southward. (Widely diffused in the Southern hemisphere.) 



8, CltSCUTA, Tourn. Doddbe. 



Calyx 5- (rarely 4-) cleft, or of 5 sepals. Corolla globular-urn-shaped, bell- 

 shaped, or somewhat tubular, the spreading border 5- (rarely 4-) cleft. Stamens 

 furnished with a scale-like often fringed appendage at their base. Ovary 2-celled, 

 4-ovuled: styles distinct, or rarely united. Pod mostly 4-seeded. Embryo 

 thread-shaped, spirally coiled in the rather fleshy albumen, destitute of cotyle- 

 dons ! sometimes with a few alternate scales (belonging to the plumule) : ger- 

 mination occurring in the soil. — Leafless herbs, chiefly annuals, yellowish or 

 reddish in color, with thread-like stems, bearing a few minute scales in place of 

 leaves ; on rising from the ground becoming entirely parasitic on the bark of 

 herbs and shrubs on which they twine, and to which they adhere by means of 

 papillae developed on the surface in contact. Flowers small, cymose-elustered, 

 mostly white ; usually produced late in summer and in autumn. (Name of un- 

 certain, supposed to be of Arabic, derivation.) 



The following account of our species is contributed by Dr. Engelmann, 

 whose monograph of the whole genus is published in Transactions of the St. 

 Louis Academy of Science. 



§ 1. Stiffmas elongated: pod opening regularly around the base by circumcissile dAis- 

 cence, leaving the partition behind. (Natives of the Old World.) 



1. C. EpfLiNUM, "Weihe. (Flax Dodder.) Stems very slender, low, 

 flowers globular, sessile in dense scattered heads ; corolla 5-parted, short-cyhn- 

 drical, scarcely exceeding the broadly ovate acute divisions of the calyx, left sur- 

 rounding the pod in fruit ; stamens shorter than the limb ; scales short, broad, 

 crenulate, shorter than the globose ovary . — Flax-fields ; in Europe very in- 

 jurious : sparingly introduced with flax-seed into the Northern States. Juno. 

 (Adv. from Eu.) 



