The Manual of the Botany of the Northern United States Part 26

2. Leavenworthia. Seed winged; embryo straight or nearly so. Annual; stem often scapose, 1--few-flowered.

3. Dentaria. Stem naked below, 2--3-leaved. Pod coriaceous, with thick placentas, long-styled. Seeds wingless; cotyledons thick, very unequal.

4. Cardamine. Stem leafy. Pod coriaceous, with thick placentas. Seeds wingless; cotyledons flattened, equal.

[+][+][+] Pod linear, or oblong, or orbicular; valves 1-nerved or nerveless. Seeds in 2 rows (except in species of n. 4).

5. Arabis. Pod long-linear, the flat or flattish valves more or less 1-nerved. Seeds winged or wingless. Flowers white to purple. Stems leafy, at least below.

6. Draba. Pod oval to narrowly oblong or lanceolate; valves flat or flattish, faintly nerved or veined. Seeds wingless, numerous.

7. Alyssum. Pod orbicular; valves veinless, somewhat convex with flattened margin. Seeds wingless, 2--4.

[*][*] Pod terete or turgid, or 4-angled by the prominent midnerves.

Seeds wingless, more or less turgid.

[+] Pods short. (See also n. 10.)

8. Lesquerella. Pod globular-inflated, about 4-seeded; valves nerveless.

Cotyledons acc.u.mbent. Flowers yellow.

9. Camelina. Pod obovoid, many-seeded; valves 1-nerved; style slender.

Cotyledons inc.u.mbent. Flowers yellow.

10. Subularia. Pod ovoid or globular, few-seeded, valves 1-nerved; style none. Cotyledons long, folded transversely. Flowers white. Dwarf stemless aquatic.

[+][+] Pod linear (or oblong or even globular in n. 10).

[++] Cotyledons acc.u.mbent.

11. Nasturtium. Pod often short; valves strongly convex, nerveless.

Seeds small, in 2 rows in each cell. Flowers yellow or white.

12. Barbarea. Pod somewhat 4-sided; valves strongly 1-nerved. Seeds in 1 row. Flowers yellow.

[++][++] Cotyledons inc.u.mbent or partially so.

13. Hesperis. Pod terete, elongated; stigma-lobes narrow, erect. Flowers large, purple.

14. Erysimum. Pod 4-sided; valves strongly 1-nerved; stigma broadly 2-lobed. p.u.b.escence of appressed 2--3-parted hairs. Flowers yellow.

15. Sisymbrium. Pod angled or teretish; valves 1--3-nerved; stigma small. Flowers yellow or white, small.

16. Thelypodium. Pod teretish; valves 1-nerved; stigma entire.

Cotyledons obliquely inc.u.mbent. Flowers rose-color. Leaves auricled.

[++][++][++] Cotyledons conduplicate.

17. Bra.s.sica. Pod beaked or pointed beyond the end of the valves, or tipped with a rigid style, nearly terete, or 4-sided. Flowers yellow or whitish.

[*][*][*] Pod short; the boat-shaped valves conduplicate or much flattened contrary to the narrow part.i.tion. Flowers white.

18. Capsella. Pod many-seeded, obcordate-triangular, wingless.

Cotyledons inc.u.mbent.

19. Thlaspi. Pod several-seeded, obovate or obcordate, winged.

Cotyledons acc.u.mbent.

20. Lepidium. Pod 2-seeded, flat, scale-shaped. Cotyledons inc.u.mbent or acc.u.mbent.

21. Senebiera. Pod 2-seeded, didymous; the valves rugose, separating at maturity from the little part.i.tion as 2 closed 1-seeded nutlets.

Cotyledons inc.u.mbent, narrow.

SERIES II. Pods indehiscent, continuous or transversely jointed; joints 1-celled.

22. Cakile. Pod short, 2-jointed; joints 1-seeded. Cotyledons plane, acc.u.mbent.

23. Rapha.n.u.s. Pod elongated, several-seeded, continuous, or constricted between the seeds and moniliform. Cotyledons conduplicate.

1. SELeNIA, Nutt.

Pod large, oblong-elliptical, flat; the valves nerveless. Seeds in 2 rows in each cell, rounded, broadly winged; cotyledons acc.u.mbent; radicle short.--A low annual, with once or twice pinnatifid leaves and leafy-bracteate racemes of yellow flowers. (Name from se????, _the moon_, with allusion to Lunaria, which it somewhat resembles in its pods.)

1. S. aurea, Nutt. Lobes of the simply pinnatifid leaves entire or toothed; pod ' long, on elongated spreading pedicels, beaked by the long slender style.--Mo. and Kan. to Tex.

2. LEAVENWoRTHIA, Torr.

Pod broadly linear or oblong, flat; the valves nerveless, but minutely reticulate-veined. Seeds in a single row in each cell, flat, surrounded by a thick wing. Embryo straight! or the short radicle only slightly bent in the direction which if continued would make the orbicular cotyledons acc.u.mbent.--Little winter annuals, glabrous and often stemless, with lyrate leaves and short 1--few-flowered scape-like peduncles. (Named in honor of the late _M. C. Leavenworth_.)

1. L. Michauxii, Torr. Scapes 2--6' high; leaf-lobes usually numerous (7--15); petals purplish or nearly white with a yellowish base, obtuse; pods not torulose, oblong to linear (6--15" long); style short.--S. Ind to Tenn. and Mo.

2. L. torulsa, Gray. Similar, but pods torulose even when young, linear; style 1--2" long; seeds acutely margined rather than winged; petals emarginate.--Barrens of Ky. and Tenn.

3. DENTaRIA, Tourn. TOOTHWORT. PEPPER-ROOT.

Pod lanceolate, flat, as in Cardamine. Style elongated. Seeds in one row, wingless, the stalks broad and flat. Cotyledons petioled, thick and very unequal, their margins somewhat infolding each other.--Perennials, of damp woodlands, with long, horizontal, fleshy, sometimes interrupted, scaly or toothed rootstocks, of a pleasant pungent taste; the simple stems leafless below, bearing 2 or 3 petioled compound leaves about or above the middle, and terminated by a single corymb or short raceme of large white or purple flowers. Flowers larger, pods broader, and seeds larger than is usual in Cardamine. (Name from _dens_, a tooth.)

[*] _Rootstock elongated; leaves 3-foliolate._

1. D. diphlla, L. Rootstock long and continuous, often branched, toothed; stem-leaves 2, similar to the radical ones, close together; leaflets rhombic-ovate or oblong-ovate, shortly petiolate, coa.r.s.ely crenate, the teeth abruptly acute; petals white.--Rich woods, Maine to Minn. and Ky. May.--Rootstocks 5--10' long, crisp, tasting like Water-Cress.

[*][*] _Rootstock tuberous, more or less moniliform; leaves 3-foliolate or 3-parted._

2. D. laciniata, Muhl. Tubers deep-seated, usually not jointed nor prominently tubercled; root-leaves often none; stem-leaves 3-parted, the lateral segments often 2-lobed, all broadly oblong to linear, more or less gash-toothed; flowers white or rose-color.--N. Eng. to Minn., Kan., and southward. April, May.--Var. MULTiFIDA, a slender form with the narrowly linear segments usually more or less divided into linear lobes.

(D. multifida, _Muhl._) Southward, scarcely if at all within our limits.