224 KEY AND FLORA 



thus forming a spike. Calyx irregularly 4^5-cleft, split down 

 the lower side. Corolla swollen below, decidedly 2-lipped, the 

 upper lip arched. Stamens projecting. 



1. C. americana Wallr. Squawroot, Cancer Root. Stems 3-6 

 in. high, yellowish or yellowish-brown. Flowers numerous, incon- 

 spicuous. Corolla dirty white or pale brown. In oak woods ; not very 

 common. 



n. OROBANCHE L. (THALESIA) 



Brownish or whitish plants, with naked scapes borne on 

 scaly, mostly underground, stems. Calyx regular, 5-cleft. 

 Corolla 5-lobed, slightly irregular. Stamens not projecting 

 from the corolla tube. 



1. 0. uniflora L. One-Flowered Cancer Root. Slightly cov- 

 ered with clammy down. Stems very short-branched, each with 1-3 

 1-flowered scapes 3-5 in. high. Calyx lobes lanoe-awl-shaped, half 

 as long as the corolla. Corolla yellowish-white, veiny, purple-tinged ; 

 palate with 2 yellow bearded ridges. Damp woods. 



2. 0. fasciculata Nutt. Stem scaly, upright, 8-4 in. high above 

 ground ai)d generally longer than the numerous 1-flowered peduncles. 

 Calyx lobes short, triangular. Parasitic on wild species of Artemisia, 

 etc., in sandy and loamy soil N.W. and W. 



93. ACANTHACE.S;. Acanthus Family 



Herbs or shrubs. Leaves opposite or whorled, without 

 stipules. Flowers zygomorphic, usually with large bracts. 

 Calyx of 4 or 5 unequal segments which considerably over- 

 lap each other. Corolla 4-5-parted and usually more pr less 

 2-lipped. Stamens usually 2 long and 2 short, sometimes only 

 2. Ovary free from the calyx. Truit usually a capsule. Seeds 

 not winged. A large family, mostly tropical, with only a few 

 insignificant wild species in the northern United States. 



I. DIAWTHERA L. 



Perennial herbs ; stem smooth. Leaves opposite, entire or 

 toothed, riowers axillary, solitary or clustered, zygomorphic. 

 Calyx 5-parted. Corolla 2-lipped ; upper lip erect, concave, 

 entire' or notched ; the lower prominently veined, spreading. 



