MUSTARD FAMILY. 59 



(5 1. Fruit a true pod, opening lengthwise by tivo valves, which fall away and leave the 

 thin, persistent partition when ripe. 



* Pod flattened parallel to the partition; the seeds flat or flattish ; seed-leaves edgewise 



to their stem. 

 +- Pod broadly oblong or oval, large and very flat ; seeds 2-4 in each cell in 2 rows. 



1. LUNARIA. Seeds winged. Large pod stalked in the calyx. Flowers purple, rather 



larffe- -- +- Pod oblong or linear ; seeds in 1 row. 



H- Valves nerveless. 



2. LEAVENWORTHIA. Stems scape-like, 1-few-flowered. Seeds winged. Small 



annuals. 



3. DENTAEIA. Stems naked below, 2-3-leaved above, from a horizontal, fleshy, scaly root- 



stock. Seeds wingless. 



4. CARDAMINE. Stems leafy, from a fibrous root, or at least not from a scaly rootstock. 



Seeds wingless. ^ ^ mves with a prominent midrib. 



5. MATTIIIOLA. Stigma deeply 2-lobed. Seeds as broad as the partition, winged. 



Flowers large and showy, white to purple. 



6. AKABIS. Stigma only slightly, or not at all, 2-lobed. Seeds winged or margined. 



-H -H +- Pod linear, oblong, or even round oval, but the seeds in 2 rows. [See, also, 



Arabis.] 



7. DRABA. Seeds wingless, numerous. Pods flat, various in shape. Flowers small and 



(in ours) white. 



8. ALYSSUM. Seeds winged, 2-4. Pods flat, roundish. Flowers small, yellow or white. 



* * Pod globular, or cylindric, or 4-angled by the prominent mid-nerves ; seeds wing- 



less. [Matthiola may be sought here.] 



+- Pod globular or cylindric. 

 H- Valves nerveless ; cotyledons accumbent. (Lessons, Figs. 425, 426.) 



9. LESQUERELLA. Pod about 4-seeded. Low, hoary plants with mostly yellow, 



small flowers. 



10. AUBRIETIA. Pod many-seeded. Stronger, hoary, with purple, rather large flowers. 



11. NASTURTIUM. Pod many-seeded. Aquatic or marsh plants, hairy or smooth, and 



small yellow or white flowers. 



H- -H- Valves nerved; cotyledons incumbent. (Lessons, Figs. 427, 428.) 



12. CAMELINA. Pod turgid, obovate, or pear-shaped. Weed, usually in flax. 



- +- Pod linear. 



H- Cotyledons accumbent. 



(11. NASTURTIUM.) Yalves nerveless. Marsh or aquatic plants. 



13. CHEIRANTHUS. Valves with a strong mid-nerve. Lateral sepals sac-like at base. 



Leaves entire and flowers showy. 



14. BARBAREA. Valves with strong mid-nerve. Sepals nearly equal and alike. Leaves 



lyrate or pinnatifid. 



- -H- Cotyledons incumbent. (Lessons, Figs. 427, 428.) 

 = Flowers purple or rose-colored, or, if white, large. 



15. HESPERIS. Stigma with 2 erect blunt lobes. Flowers pink-purple. Hairs glandular. 



16. MALCOLM I A. Stigma with 2 pointed lobes. Hairs glandless. 



17. THELYPODIUM. Stigma entire. 



= = Flowers yellow, or, if white, very small. 



18. ERYSIMUM. Stigma rather large and 2-lobed. Leaves simple. 



19. SISYMBRIUM. Stigma small and entire. Leaves twice pinnatifld. 



m tf Cotyledons conduplicate. 



20. BEASSICA. Pod more or less beaked. Flowers yellow. 



