102. Gentianageae 187 



1. Centaurium Hill — Centaury 

 C. pulchellum (Sw.) r3rucc. Wet ground, nat. from Eur.; Cook 

 Co. June-Sept. 



2. Sabatia Adans. — Rose-gentian 

 1. Branches opposite; stem 60-90 cm tall; calyx about half the length 

 of the corolla, the calyx- tube about 2 mm long; moist ground, 



locally throughout 111., except the n.w. counties. July-Aug 



S. angiilaris (L.) Pursh 



1. Branches chiefly alternate; stems 15-40 cm tall; calyx about as 

 long as the corolla, the calyx- tube 5-ribbed, 5-6 mm long; 

 prairie soil, rare; Peoria Co., McDonald; Washington Co., 

 Eggert S. campestris Nutt. 



3. Gentiana L. — Gentian 

 1. Annuals; corolla without plaits or teeth in the sinuses. 

 2. Corolla-lobes fringed or dentate; flowers 3-5 cm long. 



3. Leaves lanceolate or ovate-lanceolate, with rounded or sub- 

 cordate bases; corolla-lobes conspicuously fringed all 

 around the summit, scarcely fringed on the sides; low 



ground, n. 111., rare. Sept. -Oct. Fringed Gentian 



G. crinita Froel. 



3. Leaves linear or linear-lanceolate; corolla- lobes shortly 

 fringed or merely dentate at the summit, fringed on the 

 sides; meadows, n. 111., rare. Aug.-Oct. Small Fringed 



Gentian G. procera Holm 



2. Corolla-lobes with entire or rarely denticulate margins ; flowers 

 1-2.5 cm long; dry soil, southward to Macoupin and Clark 



counties. Aug.-Oct. Stiff Gentian G. quinqucjolia L. 



1 . Perennials ; corolla with membranous toothed or lobed plaits in the 



sinuses. 



4. Margins of leaves and calyx-lobes microscopically scabrous or 



ciliate; corolla usually blue. 



5. Anthers separate or merely connivent; dry ground, chiefly in 



the northern half of the state, but extending southward to 



Washington and Marion counties. Sept. -Oct. Downy 



Gentian G. puherula Michx. 



5. Anthers cohering in a ring or short tube. 



6. Corolla-lobes distinct, longer than or equalling the plaits; 

 wet ground, rare; n.e. 111.; also Pope Co. Aug.-Oct. 



Soapwort Gentian G. saponaria L. 



6. Corolla-lobes none or minute, the plaits very broad; moist 



ground, rare. Aug.-Oct. Closed Gentian 



G. andrewsii Griseb. 



4. Margins of leaves and calyx-lobes smooth or nearly so; corolla 

 yellowish-white; moist soil, rare, extending southward to St. 

 Clair and Wabash counties. Aug.-Oct. Yellowish Gentian 

 G. flavida A.Gray 



