rsC 



y 



54 Spring Flora of Ohio. 



A. Pctah "vhi/c, Ifai'fs undivided, 0}pinnatifid. 



Ror'-ip-a a-mer-i-ca'-na (Gr.) Britt. (Nasliir/iidii laciistre Gr.) 

 Lake Cress. — Aquatic; leaves oblong, entire, serrate or pinnatifid, the 

 immersed ones dissected into capillary divisions ; pod ovoid, a little 

 longer than the style; flowering later than the preceding species. 



Ror'-ip-a ar-mo-ra'-ci-a (L.) Hitch. {Nasturtium armoracia Fr.) 

 Horse-radish. — Root-leaves very large, oblong, crenate, rarely pinnatifid, 

 those of the stem lanceolate ; pods globular (.seldom formed.) 



(). Genus CAR-DA-MI'-NE. — Pod linear, flattened, the partition and 

 placentas thick, seeds in a single row in each cell ; flowers white or 

 purple. 



A. Leaves simple. 



Car-da-mi'-ne bul-bo'-sa (Schreb.) B. S. P. [C. rhomboidea DC.) 

 Spring Cress. — Stems simple, upright, from a tuberous base, the slen- 

 der rootstock bearing small tubers; root-leaves round, often cordate, 



f lower stem-leaves ovate or rhombic-oblong, the upper sub-lanceolate 



/ and sessile ; flowers large", white. 



Kii 



Car-da-mi'-ne doug-las'-si (Torr.) Britt. [C. rhoniboidca var. pur- 

 purea Torr.) Purple Spring Cress. — Low, -l-C) in. high, usually sub- 

 pubescent; flowers rose-purple, appearing very early. 



\\ Car-da-mi'-ne ro-tun-di-fo'-ii-a Mx. Mountain Water Cress. Stems 

 branching, weak or decumbent, making long runners, root fibrous; 

 leaves roundish, angled, often cordate, .petioled; flowers white, not 

 large. 



A. Leaves pinnate. 



Car-da-mi'-ne pra-ten'-sis L. Cuckoo-Flower. — Flowers showy, petals 

 thrice the length of the calyx ; leaflets of the lower leaves rounded and 

 stalked, those of the upper oblong or linear. Northward ; perhaps in- 

 correctly reported for Ohio. 



Car-da-mi'-ne hir-su'-ta L. Small Bitter Cress. -Flowers small, white; 

 stems o-'iO in. high, erect or spreading from the spreading cluster of 

 root-leaves; pedicels nearly or quite erect and the pods appressed. 

 This species has been reported for Ohio, but it is very rare according 

 to Prof. Britton, and it is likely that the following has been mistaken 

 for it. 



