RUCIFER^E. (MUSTARD FAMILY.) 31 



pods ovoid, one-celled, a little longer than the style. }\. (N. natans, ed. 1 . N. natans, 

 var. Americanum, Gray. Armoracia Americana, Am,} Lakes and rivers, 

 N. New Fork to Illinois and Kentucky. July. 



8. N. ARMORACIA, Fries. (HORSERADISH.) Root-leaves very large, ob- 

 long, crenate, rarely pinnatifid ; those of the stem lanceolate ; fruiting pedicels 

 ascending; pods globular (seldom formed); style very short. 1J. (Cochlearia 

 Armoracia, L.) Boots large and long; a well-known condiment. Escaped 

 from cultivation into moist ground. (Adv. from Eu.) 



2. IODAWTHUS, Torr. & Gray. FALSE ROCKET. 



Pod linear, elongated, terete ; the valves nerveless. Seeds in a single row in 

 each cell, not margined. Cotyledons accumbent. Claws of the violet-purple 

 petals longer than the calyx. A smooth perennial, with ovate-oblong pointed 

 and toothed leaves, the lowest sometimes lyrate-pinnatifid, and showy flowers in 

 panicled racemes. (Name from uoSqs, violet-colored, and avdos, /lower.) 



1. I. hespeiidoides, Torr. & Gray. (Hesperis pinnatifida, Michx.) 

 Banks of rivers, west of the Alleghanies. May, June. Stem l-3 high. 

 Petals 5" long, spatulate. Pods 1' to'nearly 2' long, somewhat curved upwards. 



3. L.EAVENWORTH1A, Torr. LEAVENWORTHIA. 



Pod linear or oblong, flat; the valves nerveless, but minutely reticulate- 

 veined. Seeds in a single row in each cell, flat, surrounded by a wing. Em- 

 bryo straight ! or the short radicle only slightly bent in the direction which if 

 continued would make the orbicular cotyledons accumbent. Little biennials or 

 hyemal annuals, glabrous and stemless, with lyrate root-leaves and short one - 

 few-flowered scapes. (Named in honor of Dr. M. C. Leavenworth, the discoverer 

 of one species.) 



1. It. IVIicliaitxii, Torr. Scapes one-flowered; petals white or purplish, 

 yellowish towards the base. (Cardamine uniflora, Michx.} On flat rocks, 

 Southeastern Kentucky (also Tennessee and Alabama, whence Prof. Hatch sends 

 it with purple flowers). March, April. 



2. It. aiirea, Torr. Scapes 1 -8-flowered; petals yellow, larger than in the 

 other (perhaps not distinct). With No. 1, and southwestward. 



4. I>ENTAItIA, L. TOOTHWORT. PEPPER-ROOT. 



Pod lanceolate, flat, as in Cardamine, but broader. Seed-stalks broad and 

 flat. Perennials, with long, horizontal, fleshy, sometimes interrupted, toothed 

 rootstocks of a pleasant pungent taste ; the low simple stems bearing 2 or 3 

 petioled compound leaves about the middle, and terminated by a single raceme 

 of large white or purple flowers. (Name from dens, a tooth.) 



1. D. diphylla, L. RootstocJc long and continuous, toothed; stem-leaves 2, 

 similar to the radical ones, close together, of 3 rhombic-ovate coarsely toothed 

 leaflets. Rich woods, Maine to Kentucky. May. Rootstocks 5' - 1 0' long, 

 crisp, tasting like Water-Cress. Flowers white. 



