140 American Midland Naturalist Monograph No. 2 



8. Alliaria Adans. — Garlic Mustard 



A. officinalis Andrz. Roadsides and waste places, adv. from Eur. May- 

 June. lAlliaria alliaria (L.) Britt.] 



9. Conringia Link 



C. orientalis (L.) Dum. Hare's-ear Mustard. Waste places, occasional; 

 adv. from Eur. May-July. 



10. Erysimum L. 



(Cheirinia Link) 

 1. Petals more than 1 cm. long; pods 4-8 cm. long; plant biennial; sandy soil, 



Cass, Mason, and La Salle counties. May-June. Western Wallflower 



E. asperum DC. 



1. Petals 4-9 mm. long; annuals. 



2. Petals 4-5 mm. long; pods erect 2-2.5 cm. long, on ascending pedicels; 

 leaves entire or nearly so; fields and waste places; chiefly in the n. half 

 of the state. June-Aug. Wormseed Mustard E. cheiranthoides L. 



2. Petals 6-9 mm. long; pods spreading, 4-8 cm. long; leaves repand-dentate 

 or denticulate; waste places, roadsides, fields, etc.; adv. from Eur. May- 

 June E. repandum L. 



11. Descurainia Webb. &: Barth. — Tansy Mustard 



(Sophia Adans.) 



D. brachycarpa (Richards.) O. E. Schulz. Sandy soil or roadsides, com- 

 mon. Apt. -June. [^Sisymbrium canescens Nutt., var. brachycarpon (Richards.) 

 Wats.} 



12. Draba L. — Whitlowcress 



1. Stem leafy -branched; pods narrowly oval, acute, 2-3 mm. long, 1 mm. wide, 

 glabrous, 6-16 seeded, equalling or exceeding the pedicels; petals entire, 



whitish, sometimes minute or none; dry soil, s. 111. Apr.-May 



D. brachycarpa Nutt. 



1. Stem scapose, the leaves chiefly basal; pods 15-60-seeded. 



2. Petals entire or emarginate, 3-5 mm. long: pods mostly longer than the 

 pedicels. 



3. Pods linear, 8-12 mm. long, 1-2 mm. wide, glabrous or hispidulous; 

 rachis and pedicels glabrous; leaves entire or nearly so; sandy soil, 



locally abundant. Apr.-May. [D. caroliniana Walt.} 



D. rcptans (Lam.) Fern. 



3. Pods oval to linear-elliptical, 6-15 mm. long, 2 mm. wide, pubescent; 

 rachis and pedicels pubescent; leaves dentate above the middle; sandy 



soil, s. 111. Mar.-May D. cuneifolia Nutt. 



2. Petals deeply 2-cleft; pods oval, glabrous, 4-10 mm. long, shorter than 

 the pedicels; cultivated ground and waste places, occasional; nat. from 

 Eurasia. Apr.-May D. verna L. 



13. Df.ntaria L. — Toothwort 

 D. laciniata Muhl. Woods, common. Mar.-May. 



