GENUS i. 



BROOM-RAPE FAMILY. 



233 



Family 30. OROBANCHACEAE Lindl. Nat. Syst. Ed. 2, 287. 1836. 



BROOM-RAPE FAMILY. 



Erect, simple or branched, brown yellowish purplish or nearly white root- 

 parasites, the leaves reduced to alternate appressed scales, the flowers perfect, 

 irregular (rarely cleistogamous), sessile in terminal bracted spikes, or solitary and 

 peduncled in the axils of the scales. Calyx inferior, gamosepalous, 4-5-toothecl, 

 4-5-cleft, or split nearly or quite to the base on one or both sides. Corolla gamo- 

 petalous, more or less oblique, the tube cylindric, or expanded above, the limb 

 2-lipped, 5-lobed. Stamens 4, didynamous, inserted on the tube of the corolla and 

 alternate with its lobes, a fifth rudimentary one occasionally present; filaments 

 slender; anthers 2-celled, the sacs parallel, equal. Ovary superior, i-celled, the 

 four placentae parietal ; ovules numerous, antropous ; style slender ; stigma discoid, 

 2-lobed, or sometimes 4-lobed. Capsule i-celled, 2-valved. Seeds numerous, 

 reticulated, wrinkled or striate ; embryo minute ; cotyledons scarcely differentiated. 



About 1 1 genera and over 200 species, of wide geographic distribution, mostly in the northern 

 hemisphere. 



Flowers all complete and perfect. 

 Calyx 2-s-lobed or toothed. 



Calyx about equally s-cleft ; no bractlets on peduncles nor calyx. i. Thalesia. 



Calyx unequally toothed, or split on both sides ; flowers bracteolate. 2. Orobanche. 



Calyx spathe-like, split on the lower side, 3~4-toothed on the upper. 3. Conopholis. 



Lower flowers cleistogamous, fertile ; upper complete, mostly sterile. 4. Leptamnium. 



i. THALESIA Raf. Am. Month. Mag. 2 : 267. 1818. 

 [ANOPLANTHUS Endl. Icon. Gen. PI. 12. pi. 72. 1838.] 



[APHYLLON A. Gray, Man. 290. 1848.] 



Glandular or viscid-pubescent simple-stemmed herbs, parasitic on the roots of various 

 plants, with scattered scales, and long-peduncled yellowish white or violet, complete and per- 

 fect flowers without bractlets. Calyx campanulate or hemispheric, nearly equally 5-cleft, the 

 lobes acute or acuminate. Corolla oblique, the tube elongated, curved, the limb slightly 

 2-lipped, the upper lip erect-spreading, 2-lobed, the lower spreading, 3-lobed, the lobes all 

 nearly equal. Stamens included ; anther-sacs mucronate at the base. Ovary ovoid ; placentae 

 equidistant, or contiguous in pairs; style slender, deciduous; stigma peltate, or transversely 

 2-lamellate. [Dedicated to Thales.] 



About 5 species, natives of North America. Type species : Orobanche uniftora L. 

 Stem very short; peduncles 1-4, erect; calyx-lobes lanceolate, acuminate. i. T. uniftora. 



Stem erect, 2' -5' high ; peduncles several ; calyx-lobes broad, acute. 2. T. fasciculata. 



i. Thalesia uniflora (L.) Britton. Pale or Naked Broom-rape. One-flowered 

 Broom-rape. Squaw-drops. Cancer-root. Fig. 3876. 



Orobanche uniflora L. Sp. PI. 633. 1753. 

 Anoplanthus uniflorus Endl. Icon. Gen. PI. 12. pi. 



72. 1838. 

 Aphyllon uniflorum T. & G. ; A. Gray, Man. 290. 



1848. 

 T. uniflora Britton, Mem. Torr. Club 5: 298. 1894. 



Stem usually less than i' long, nearly subter- 

 ranean, bearing several ovate-oblong scales and 

 1-4 slender erect scape-like glandular-puberulent 

 naked i -flowered peduncles 3'-8' high. Calyx 

 campanulate, pubescent, glandular, 4"-s" high, 

 less than one-half the length of the corolla, its 

 lobes as long as the tube or longer, lanceolate, 

 acuminate ; corolla white or violet, puberulent 

 without, 8"-i2" long, the curved tube about 3 

 times as long as the limb, the short lobes oval 

 or obovate, obtuse ; placentae nearly equidistant ; 

 capsule ovoid, longer than the calyx. 



In woods and thickets, parasitic on the roots of 

 various herbs, Newfoundland to Ontario, South 

 Carolina and Texas. Far western plants, formerly 

 referred to this species, prove to be distinct. 

 Pipes. April-June. 



