CRUCIFEE^E. 25 



(about half an inch in length), Some of them more or less confluent : racemes erect, 

 densely many-flowered, 3 to 5 inches long : corolla white or cream-color with bluish 

 tips; the straight spur half an inch long, horizontal or ascending, very obtuse, 

 exceeding the rest of the flower : capsule oval or oblong, turgid, tipped with a 

 slender style : seeds shining, crestless. Proc. Am. Acad. x. 69. 



Moist and shady ravines in the Sierra Nevada, near Truckee (Bolander) : thence to Plumas 

 Co., E. L. Case (for whom it is named), Lemmon, &c. Also in S. Colorado, Brandegee. 



ORDER VII. CRUCIFERffil. 



Herbs, with a pungent watery juice, cruciform corolla, tetradynamous stamens, a 

 2-celled pod (silicle) with 2 parietal placentae, and an embryo filling the seed, with 

 cotyledons (accumbently or incumbently) applied against the radicle. Flowers per- 

 fect, hypogynous. Calyx of 4 sepals, deciduous. Petals 4, usually with narrowed 

 base or claw, and the lamina spreading, so forming a cross, rarely wanting. Stamens 

 6, two of them inserted lower down on the receptacle and shorter than the other 

 four. Ovary 2-celled by a partition which stretches across from the placentae, rarely 

 1 -celled by its abortion. Style undivided or none : stigma entire or 2-lobed. 

 Fruit the peculiar capsule or pod named a silique, or when short a silicle ; the 2 

 valves falling away from the placentae and partition, which persist, forming what is 

 called a replum, in a few genera indehiscent. Ovules few or numerous, sometimes 

 solitary, carnpylotropous. Seeds with a smooth coat ; albumen none. Cotyledons 

 either accumbent (i. e. applied edgewise to the radicle) or incumbent (i. e. with the 

 radicle against the back of one of them), usually plane, sometimes (as in Mustard) 

 folded or wrapped around the radicle. Flowers generally in racemes and the pedicels 

 without any bract. Leaves alternate, without stipules : no glandular pubescence. 



A large family, comprising about 175 genera, and between one and two thousand known species, 

 distributed over all parts of the world, but few in the tropics, and most in the temperate and 

 colder regions. Nearly all are innocent, except for the excessive pungency or acridity of the seeds 

 of Mustard and the root of Horse-radish ; several furnish condiments ; and Cabbage, Turnips, &c., 

 are staple articles of food. The order is so strictly natural that generic distinctions are difficult. 



I. Pod regularly dehiscent, 2-valved. 



* Pod strongly compressed parallel with the broad partition : cotyledons accumbent. 

 H- Pod short ; valves nerveless or faintly 1 -nerved : flowers white or yellow. 



1. Platyspermum. Pod large, orbicular, 8-12-seeded; valves flat, nerveless. Seeds broadly 



winged. Dwarf glabrous annual, with 1 -flowered scapes: flowers small, white. 



2. Alyssum. Pod small, orbicular, 2 - 4-seeded ; valves convex, nerveless. Seeds wingless. 



Canescent, branching : flowers racemose. 



3. Draba. Pod ovate to oblong or linear, few - many-seeded ; valves flat or convex. Seeds 



wingless. Low : flowers racemose. 



i f- Pod elongated. 



n- Valves nerveless ; replum thickened : seeds wingless : flowers white or rose-color, mostly 

 large : leaves all petioled : stems usually from running rootstocks or small tubers. 



4. Dentaria. Pod with elongated beak and very stout replum. Seed turgid. Stem few-leaved 



near the summit : raceme short : glabroxis. 



5. Cardamine. Pod moderately beaked or pointed, less stout. Seed more flattened. Stems 



leafy, with elongated racemes. 



++ -n- Valves 1 -nerved ; replum thin : seeds flat, often winged or margined : flowers white to 

 purple (yellow in one species of Chciranthus) : leaves entire or toothed, the cauline 

 sessile : root perpendicular. 



6. Arabia. Anthers short, scarcely emargiuate at base. Petals with a flat blade and claw. 



Calyx short or narrow, rarely colored. Seeds in 1 or 2 rows. 



