Mustard Family. 11 



Akabis. Pod flat, long-linear: seeds winged or wingless; flowers white or purple. 



Dkab*. Pod oval to narrowly lanceolate, flat; nowe.'s racemose. 



Dentarla. Stem simple, mostly naked. 



CrtRDAMiNB. Stem leafy ; pod linear. 



AiA'SSUM. Pod orbicular, thin margined. 4 seeded. 



C *jieljna. Pod pear-shaped, seeds numerous : flowers yellow. 



* * * * Pod Indehlscent. 

 RvPHaNos. Pod elongated, long pointed, constricted; seeds cushioned. 



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

 stock, clustered pinnatifld 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 Parse. Stem 4-2U 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 pinnatind, 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 pepper wort or peppergrass. 



L. virginicum L. Wild P. Plant leafy, somewhat branched: stem 0-20 

 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 preceding but stem less leafy and 

 more bushy-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. apctalum Willd.) 



THL-ASPI 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, 15-18 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 K. Br. Water Ckess. Glabrous, usually marsh or aquatic 

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

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

 less valves. Seeds in 2 imperfect rows, marginless. 



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



N Ddlustre D C. Marsh. C. Plant 1-3 feet high, erect, simple or much 

 branched, usually smooth; leaves oblong-lanceolate, pinnately cleft or 

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

 pedicels ovord or oblong. Shallow water or moist depressions; June-Septem- 

 ber; common. ( Rorlpa patustrti ( L ) Bess.) 



N. hispidum D C. Similar to the preceding; stem stouter, often i feet 

 hiffh 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. hispida ( Desv.) Britton.) 



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

 obovate or oblong, obtusely incised, crenate, or nearly entire; flowers 

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



