Mustard Family. 11 



Akabis. Pod Hat. long-linear; seeds winged or wingless; flowers white or purple. 



DKaB\. Vod oval to narrowly lanceolate, Hat : Howe s laeeniose. 



DBNTARIA. Stem simple, mostly naked. 



Chiu.mink. Stem leafy: pod linear. 



AL.YSSUM. Pod orbicular, thin margined. 4 seeded. 



i',mhi,i.\a. Pod pear-shaped, seeds numerous: flowers yellow. 



* * * * Pod huh hisceul. 

 R«phaNus. Pod elongated, long pointed, constricted ; seeds cushioned. 



CAPSELLA Medic. An erect annual herb, with a long descending- root- 

 stock, clustered pinnatifid or toothed root-leaves, the cauline sessile, saggitate, 

 and small white racemose flowers. Pods obcordate, many-seeded, long pedi- 

 cel led. 



C. bursa-pastoris ( L.) Moench. Shepherd's Purse. Stem 4-20 inches high, 

 pubescent below, more or less glabrous above. Fields and waste places: 

 April-October: a very common weed. (Bursa bursa-pastoris ( L) Britton.) 



LEPIDIUM L. Annual or biennial herbs with pinnatifid. lobed. or entire 

 leaves and small white or whitish racemose flowers. Stamens 2 in our 

 species. Pods roundish, flat, notched above, 1 seed in each cell. Weeds, 

 commonly known as pepperwort or peppergrass. 



L. virginicum L. Wild P. Plant leafy, somewhat branched: stem 6-20 

 inches high; leaves cut-serrate. Petals usually present: pods marginless or 

 nearly so. on slender pedicels: cotyledons accumbent. Fields and waste 

 places, preferring moist shady places: May-October: common. 



L. intermedium Gray. Similar to the preceeding but stem less leafy and 

 more bush3'-branched. nearly entire: petals minute or wanting; pods wing- 

 margined at the top; cotyledons incumbent. Dry or sterile soil, fields and 

 pastures: May-September; very common. (L. apebaVum Willd.) 



TriLASPI L. Low herbs, with undivided leaves, the basal forming a 

 rosette, those of the stem auriculate. clasping, and small white or purplish 

 racemose flowers. 



T. arvense L. Field Penny-cress. Annual, (i-18 inches high, smooth, sim- 

 ple or branched above; basal leaves petioled, oblanceolate, early deciduous, 

 stem leaves oblong or lanceolate, remotely dentate: flowers white: pods flat. 

 nearly orbicular, broadly winged, notched at the apex; seeds about 6 in each 

 cell. Waste places: rare: Muscatine county. 



NASTURTIUM R. Br. Water Cress. Glabrous, usually marsh or aquatic 

 plants, with deeply incised or pinnatifid leaves, and white or yellow flowers. 

 Pods oblong-linear to almost globular, terete or teretish, with convex nerve- 

 less valves. Seeds in 2 imperfect rows, marginless. 



* Annual or biennial; roots simple, fibrous; Hovers small, yellow or yellowish. 



IN. palustre D C. Marsh C. Plant 1-3 feet high, erect, simple or much 

 branched, usually smooth: leaves oblong-lanceolate, picnately cleft or 

 parted: pedicels about one-fourth inch long: pods erect, shorter than the 

 pedicels, ovoid or oblong. Shallow water or moist depressions: June-Septem- 

 ber: common. | Boripa paliistris ( L ) Bess.) 



IS. hispidum DC. Similar to the preceeding: stem stouter, often 4 feet 

 high, hirsute: leaves lyrate-pinnatifid. hirsute on the veins beneath: pedicels 

 slender, spreading, longer than the ovoid or globose pod. Wet places: July; 

 reported from Scott county. ( R. hisptda ( Desv.) Britton.) 



N. sessiliflorum Xutt. Stem erect, simple, 1-2 feet high: leaves petioled, 

 obevate or oblong, obtusely incised, crenate, or nearly entire: flowers 

 small, nearly sessile: pods about one-half inch long or less, thick, pedicel led. 



