GENERA OR FAMILIES. 145 



4. Cistaceous Plants. Cistace^. 



(16) Helianthemum — two outer sepals smaller ; petals deciduous 



capsule three-valved. 



5. Resedaceous Plants. Uesedace^e. 



(17) Reseda — flowers in racemes ; stamens indefiDite, but not 



numerous, about 8-24, inserted on a glandular disk. 



6. Cruciferous Plants. Cruciferj?.. 



* Fruit a silique or pod, linear or linear-lanceolate, usually 

 much longer than hroad. 



t Pods tivo-valved^ with a dissepiment. 



X Style not forming a stout conical heah. 



§ Calyx conspicuously hisaccate at the base. 



(18) Matthiola — pod round or compressed ; stigma sessile, two- 



lobed, the lobes erect, gibbous or horned at the back. 

 (10) Hesperis — pod quadrangular or sub-compressed, the valves 

 keeled, somewhat three-nerved; stigma nearly sessile, of 

 two closely-converging erect elliptical obtuse lobes. 



§§ Calyx equal at the base, or very slightly gibbous. 



(20) Erysimum — pod tetragonal, the valves prominently keeled, 

 with one longitudinal nerve ; stigma obtuse, entire or 

 slightly emarginate ; seeds in a single row ; calyx erect. 



("21) Sisymbrium. — pod terete, or angled ; valves convex, with 

 three longitudinal nerves ; stigma entire ; seeds in a single 

 row, smooth ; calyx spreading. 



(22) Nasturtium — pod nearly cylindrical, short, the valves con- 

 vex, almost nerveless ; stigma capitate ; seeds irregularly 

 in two rows. 



(28) Barbarea — pod tetragonal, somewhat compressed, the valves 

 convex, with a prominent longitudinal nerve ; stigma capi- 

 tate ; seeds in a single row. 



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