MUSTARD FAMILY. 59 



$ 1. fruit a true pod, opening lengthwise by two valves, which fall away and leave the 



thin, persistent partition when ripe. 

 . Pod flattened parallel to the partition; the seeds flat or flatfish ; seed-leavet 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 



Iarge> -i- -- Pod oblong or linear ; seeds in 1 row. 



++ Valves nerveless. 



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



annuals. 



8. DENT AKIA . Stems naked below, 2-8-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. ^ ^ Valveg tpith a prominent midrib . 



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



Flowers large and showy, white to purple. 



6. ARABIS. Stigma only shghtly, or not at all, 2-lobed. Seeds winged or margined. 



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



Arabis.] 



1. DBABA. Seeds wingless, numerous. Pods flat, various in shape. Flowers small and 

 (in ours) white. 



8. ALTSSUM. Seeds winged, 2-4. Pods flat, roundish. Flowers small, yellow or whtye. 

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



less. [Matthiola may be sought here.] 



-t- Pod globular or cylindric. 

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



9. LE8QUERELLA. 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. 42T, 428.) 



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



+- +- Pod linear. 



H- Cotyledons accumbent. 



(11. NASTURTIUM.) Valves 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 pinnatifld. 



-H- ++ Cotyledons incumbent. (Lessons, Figs. 42T, 428.) 

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



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



16. MALCOLMIA. Stigma with 2 pointed lobes. Hairs glandless. 



17. THELYPODIUM. Stigma entire. 



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



18. ERY8IMUM. Stigma rather large and 2-lobed. Leaves simple. 



19. 8I8YMBRIUM. Stigma small and entire. Leaves twice pinnatifld. 



Cotyledons conduplicate. 



20. BEAS8ICA. Pod more or less beaked. Flowers yellow. 



