424 



CRUCIFERAE (MUSTARD FAMILY) 



P 



3. LOBDXARIA Desv. SWEET ALYSSUM 



Pod as in Alyssum. Petals white, entire. Cotyledons accumbent. Hairs of 

 the stem and leaves 2-pointed, appressed, attached in the middle. (Latin 

 lobulus, a little lobe, probably referring to the 2-lobed hairs. ) 



1. L. MARITIMA (L.) Desv. Slightly hoary ; leaves linear ; flowers small, 

 honey-scented. (Alyssum Lam. ; Koniga R. Br.) Often cultivated, and occa- 

 sionally spontaneous. (Introd. from Eu.) 



4. ALYSSUM [Tourn.] L. 



Pod small, orbicular, with only one or two wingless seeds in a cell ; valves 

 nerveless, somewhat convex, the margin flattened. Flowers yellow or white. 



Cotyledons accumbent. Plant stellate-pubescent. (Greek name 



of a plant reputed to check hydrophobia, as the etymology 



denotes. ) 



738 A alyssoides *' ^' ALT88O * DES ^- Dwarf hoary annual, with linear- 

 Pod with persi< tent 8 P atu ' ate l eave s, pale yellow or whitish petals little exceeding 

 calyx xV the persistent calyx, and orbicular sharp-margined 4-seeded 



pod, the style minute. (A. calycinum L. ) Occasional in 

 grass-land. (Adv. from Eu.) FIG. 738. 



5. LESQUERELLA Wats. 



Pod mostly globular or inflated, with a broad orbicular to ovate hyaline par- 

 tition nerved to the middle, the hemispherical or convex thin valves nerveless. 

 Seeds few or several, in 2 rows, flat. Cotyledons accumbent. Filaments 

 toothless. Low herbs, hoary with stellate hairs or lepi- 

 dote. Flowers mostly yellow. (Named for Leo Lesque- 

 reux, distinguished bryologist and paleobotanist, 1805- 

 1889.) 



1. L. glob6sa (Desv.) Wats. Minutely hoary all over: 

 stems spreading or decumbent from an annual or biennial 

 root ; leaves oblong or lanceolate, with a tapering base, 

 repand-toothed or nearly entire ; raceme at length elon- 

 gated, with filiform diverging pedicels ; petals light yellow ; 

 style filiform, much longer than the small globose acutish 

 about 4-seeded pod ; seeds marginless. 

 ( Vesicaria Shortii Torr. ) Rocky banks, 

 Ky. and Tenn. May, June. FIG. 739. 



2. L. arg6ntea (Pursh) MacM. Bien- 

 nial or perennial ; pubescence compact ; leaves linear-oblance- 

 olate, mostly entire; pods pubescent, pendulous on recurved pedi- 

 cels; style long. (L. ludoviciana Wats.) Minn, to Neb. and 

 southwestw. 



3. L. grdcilis (Hook.) Wats. Annual, slender ; pubescence 

 very fine ; leaves narrowly oblanceolate ; pods glabrous, suberect 

 on ascending or curved pedicels, stipitate ; style long. ( Vesicaria 



Hook.) Mo. and Kan. to Tex. FIG. 740. 



6. THLASPI [Tourn.] L. PEHNY CRESS 



Pod orbicular, obovate, or obcordate, flattened contrary to the narrow par- 

 tition, the midrib or keel of the boat-shaped valves extended 

 into a wing. Seeds 2-8 in each cell. Cotyledons accurabent. 

 Petals equal. Low plants, with root-leaves undivided, stem- 

 leaves arrow-shaped and clasping, and small white or purplish 

 flowers. (Name from 0\d.fiv, to crush, from the flattened 

 pod.) 



1. T. ARVENSE L. (FIELD P. or MITHRIDATE MUSTARD.) 741. T. arvense. 

 Smooth annual ; lower leaves wing-petioled, the upper sagit- Pod x */* 



789. L. globosa. 

 Part of fruiting raceme 



740. L. gracffis. 



Part of fruiting 



raceme x l / s . 



