Drnhn CRUCIFER/K. 27 



25. Physaria. Pod iliilymous ; ci-lls nenily glolniliir. StPllatP-cannsccnt i>orpnnials, with entire 



loiivos. 



II. I'od of 2 inilcliisccnt itUs, sp|mrnting at maturity fmiii tlio persistent axis. 



26. Senebiera. Oils small, gloIx)se, rugose or tiiliorcwlate. Sceij turgid ; cotyledons incum- 



bent. Flowers white, minute, in racemes opposite to the pinnatilid leave-s. 



27. Biscutella. Cells flat, nearly orbicnlnr. Seeaa flat. Flowers rather large. Stigma dilated 



01- ctinical, neaily sessile. 



III. Pod indelii.s<cnt, l-celled or transversely jointed. 



28. Thysanocarpufl. Pod small, plano-convox, nrhiiMilnr, wingi-il or margined, l-seoded. 



Slender nnnuais. 

 20. RaphanuB. Pod elongated, terete or neeklare-form, attenuated alx)ve, several-seeded. 

 L'oarso introduced annuals or biennials. 



1. PLATYSPERMUM, Hook. 

 Pod orbicular, flat, witli flat mn-velcsa valves and hyaliiio partition. Seeds few, 

 orbicular, flat and broadly margined with a thin wing; cotyledons accumbent. 

 Sopal.*! o([ual, sproadiiig. Potal.s obovate, scarroly clawed. — A low dolicato annual ; 

 with radical .^siiniilo or pinnatilid leaves, and several slender I-flowerod scapes ; 

 flowers small, white. 



1. P. scapigerum, Hook. rtlabmus : leaves usually runcinately pinnatilid: 

 scapes 2 to 3 in(;hes high : flowers erect or nodding : pod 8- 12-seeded. — FI. i. 68, 

 t. 18. 



On dry hillsides in the .sliado of larger plants, in early spring ; of short duration. Sierra Co. 

 {Lemmon) ; Stcanilmnt Springs, Nevada {IfaLwn) ; and northward to the Columhiiu 



2. ALYSSUM, Tourn. 



Pod oval or orbicular, compressed ; valves convex and nerveless. Seeds I or 2 



in each cell ; cotyledons accumbent. Sepals equal. Petals white or yellow. 



Longer filaments often toothed. — Low herbs, stellate-canesccnt, mostly with simple 



leaves. 



A large genus of the Eastern Continent, a few of its species widely naturalized weeds or readily 

 escaping from cultivation. 



1. A. calycinum, Linn. Annunl, l)ranc]iing from tlie roof, flie stems mostly 

 simple, decunilient at base, ^ to 1 foot high: leaves entire, linear-sj)atulatc, 6 to 12 

 lines long : flowers small, in slender racemes, tlio white or pale yellow petals but 

 little exceeding the short sepals : pods orbicular, with a thin margin, slightly emar- 

 ginate above, 1^ lines in diameter, a little exceeding the persistent sepals, pubescent, 

 4-seeded, on spreading pedicels a line long : stylo half a lino long. 



A native of Southern Europe, sparingly naturalized about the Ray of San Franeiseo. 



2. A. maritimum, Linn. Perennial, somewhat cnnescent with appressed silky 

 hairs, the numerous stems branching, a foot higli or less, a.srendiug or decumbent : 

 leaves lanreniatc-spatulate, entire : flowers 2 lines long, the broad white petals twice 

 longer than the deciduous sepals : ])od orbicular, a line broad, nearly smooth, 

 pointed with the slender style, 2-seeded : pedicels slender, 3 to 4 lines long, spread- 

 ing horizontally. 



Often cultivated for its fragrant flowers under the name of Stveel Afyssunu Native about th« 



Mediterranean ; sparingly naturalized near O.iklnnd. 



3. DRABA, Linn 

 Pod oval to oblong or linear, flat ; valves nearly flat, nerveless or faintly 1 -nerved. 

 Seeds few to many, in 2 rows in each cell. wingles.s ; cotyledons ac^-umbent. Sepals 



