424 



CRUCIFERAE (MUSTARD FAMILY) 



3. LOBULARIA 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 



1%s of a plant reputed to check hydrophobia, as the etymology 



I denotes.) 



738 A alyssoides * A> A LYSSOIDES L. Dwarf hoary annual, with linear- 

 Pod with persistent s P atulate leaves, pale yellow or whitish petals little exceeding 

 calyx x 2 /. 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. globbsa (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, J89. L. globow. 

 Ky. and Tenn. May, June. FIG. 739. Part of frultin s raceme 



2. L. argentea (Pursh) MacM. Bien- x /3> 



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. gracilis (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. PENNY 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 accumbent. 

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

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

 flowers. (Name from 6\deii>, 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 2 / 3 . 



740. L. gracffls. 



Part of fruiting 



raceme x 2 / 3 . 



