238 
IOWA ACADEMY OF SCIENCES. 
GENTIANACE^E. 
Gentiana L. Gentian. 
419. G. detonsa Rottb. Collected but once in low 
ground near Armstrong. 
420. G. quinquefolia occidentalis (A. Gray) Hitchcock. 
Rare in woods near Estherville. 
421. G. puberula Michx. Frequent on rather high prai- 
ries. 
422. G. andfewsii Griseb. Low ground; our common- 
est species. 
MENYANTHACEJE. 
Menyanthes L. Buck Bean. 
423. M. trifoliata L. Frequent in bogs. 
APOCYNACE^E. 
Apocynum L. Dogbane. 
424. A. androscemifolium L. Common in woods; 
branches widely spreading. 
425. A . cannabinum L. Common in woods and on low 
prairies. 
ASCLEPIADACE^E. 
Asclepias L. 
426. A. tuberosa L. Pleurisy-root. Common on dry 
prairies. 
427. A. incar nata L. Swamp Milkweed. Common in 
low ground. 
428. A. sullivantii Engelm. Frequent on low prairies. 
429. A . syriaca L. (A. cornuti L.) Common Milkweed 
or Silkw r eed. Common near woods. 
430. A. speciosa Torr. Showy Milkweed. Common on 
prairies, where it takes the place of the preced- 
ing species which has much smaller flowers. 
431. A. ovalifolia Decaisne. Dry woods and prairies; 
frequent. 
