234 



OROBANCHACEAE. 



VOL. III. 



2. Thalesia fasciculata (Nutt.) Britton. 



Clustered or Yellow Cancer-root. 



Fig- 3877. 



Orobanche fasciculata Nutt. Gen. 2: 59. 1818. 

 Anoplanthus fasciculatus Walp. Rep. 3: 480. 



1844-45. 

 Aphyllon fasciculatum A. Gray, Syn. Fl. 2: Part 



i, 312. 1878. 

 Thalesia fasciculata Britton, Mem. Torr. Club 5 : 



298. 1894. 



Stem erect, 2'-$' high, densely glandular- 

 pubescent, bearing several scales and 3-15 

 naked i-flowered peduncles i'-4' long. Calyx 

 glandular, broadly campanulate, 3"-s" high, 

 about one-third the length of the corolla, its 

 lobes triangular-lanceolate or triangular-ovate, 

 acute, equalling or shorter than the tube; co- 

 rolla nearly i' long, purplish to yellow, puberu- 

 lent without, the curved tube 3 times as long- 

 as the limb, the lobes oblong, obtuse, the limb 

 more manifestly 2-lipped than in the preced- 

 ing species ; capsule ovoid to globose. 



In sandy soil, parasitic on the roots of various 

 plants, mostly composites, northern Indiana to 

 Minnesota, Yukon ;and British Columbia, Ne- 

 braska, Arizona and California. April-Aug. 

 Thalesia lutea (Parry) Rydb. [Thalesia fasciculata lutea (Parry) Britton] is a race with light 

 yellow flowers, growing on grasses in western Nebraska and Wyoming. 



2. OROBANCHE [Tourn.] L. Sp. PI. 632. 1753. 



Glandular-pubescent, erect simple or branched, reddish yellowish violet or nearly white 

 herbs, parasitic on the roots of various plants, with scattered scales, and spicate or racemose, 

 complete and perfect, bracted and sometimes bracteolate flowers. Calyx split both above 

 and below, nearly or quite to the base, the divisions 2-cleft or rarely entire, or more or less 

 unequally 2-S-toothed. Corolla oblique, strongly 2-lipped ; upper lip erect, emarginate or 

 2-lobed ; lower lip spreading, 3-lobedi Stamens included ; anther-sacs mostly mucronate at 

 the base. Placentae equidistant, or approximate in pairs. Style slender, commonly persistent 

 until after the dehiscence of the capsule; stigma peltate to funnelform, entire, or laterally 

 2-lamellate. [Greek, Choke-vetch.] 



About 90 species, natives of the Old World and western America. Besides the following some 

 6 others occur in the western parts of North America. Type species : Orobanche major L. 



Calyx 4-toothed ; stems mostly branched. i. O.ramosa. 



Calyx split on both sides ; stem simple. 2. O. minor. 



Calyx 5-cleft ; stem simple. 3. O. ludoviciana. 



i. Orobanche ramosa L. Hemp or Branched 

 Broom-rape. Fig. 3878. 



Orobanche ramosa L. Sp. PI. 633. 1753. 



Plant yellowish; stem rather slender, branched, or 

 rarely simple, 3'-is' high, the scales few and distant, 

 2"-5" long. Spike loosely many-flowered, denser 

 above than below, the lowest flowers short-pedi- 

 celled ; bracts usually 3, the longest about equalling 

 the calyx; calyx 4-toothed, the teeth triangular- 

 ovate, acute, or acuminate, about as long as the tube ; 

 corolla 5 "-9" long, the tube yellow, slightly con- 

 stricted above the ovary, the limb bluish. 



Parasitic on ,the roots of tomato, hemp and tobacco, 

 New Jersey, Illinois, Kentucky. Adventive or natural- 

 ized from Europe. Summer. Strangle-tare. 



Orobanche purpurea Jacq., another European species, 

 with violet flowers and a s-toothed calyx, is recorded as 

 found on Achillea in lawns a'; Wingham, Ontario. 



