48 Introduction to Botany. 



() Pods linear, flattened; valves mostly nerveless; leafy throughout. 



CARDAMINE V. 



(c) Stems leafless below, from horizontal, tuberous rootstocks. DENTARIA VI. 



(d) Pods broadly linear, nerveless; stems low and scapelike. 



LEAVENWORTHIA VIII. 

 (*) Pods linear; valves mostly i-nerved; seeds usually winged or margined. 



ARABIS XIII. 

 ods more or less compressed at right angles to the partition. 



(a) Pod short, flat, rounded, 2-seeded. LEPIDIUM I. 



Pods terete or turgid. 



(6) Pods elongated, often angled; valves i-3-nerved. SISYMBRIUM II. 



FLOWERS, YELLOW. 



I. SEEDS IN 2 ROWS IN EACH CELL. 



Pods more or less compressed parallel with the partition. * 



(a) Leaves pinnatifid; valves thin, finely veined and nerveless. SELENIA VII. 



(b) Low-tufted herbs, often with stellate pubescence. DRABA XII. 



(c) Pods obovoid or pear-shaped; valves i-nerved. CAMELINA XI. 

 Pods terete or turgid. 



(a) Pods elongated, often angled; valves i-3-nerved. SISYMBRIUM II. 



(<5) Pods globular to oblong-linear; valves nerveless. NASTURTIUM IV. 



(c) Pods globular-inflated; leaves simple with stellate hairs. LESQUERELLA IX. 



(d) Pods obovoid or pear-shaped; valves i-nerved. CAMELINA XI. 



II. SEEDS IN I ROW, OR SINGLE IN EACH CELL. 



Pods terete or turgid. 



(a) Pods elongated, often angled; valves i-3-nerved; style or beak short. 



SISYMBRIUM II. 



(b) Pods elongated, tipped with a stout beak; valves i-s-nerved; lower leaves pin- 



natifid, upper leaves dentate or entire. BRASSICA III. 



FLOWERS, PURPLE. 



I. SEEDS IN 2 ROWS IN EACH CELL. 



Pods more or less compressed parallel with the partition. 



(a) Pods linear; seeds often wing-margined. ARABIS XIII. 



II. SEEDS IN I ROW IN EACH CELL. 



Pods more or less compressed parallel with the partition. f 



(a) Pods linear and flattened; valves mostly nerveless; leafy throughout. 



CARDAMINE V. 



(b) Stems leafless below, from horizontal tuberous rootstocks. DENTARIA VI. 

 (<:) Pods broadly linear, nerveless ; stems low and scapelike. 



LEAVENWORTHIA VIII. 

 (d) Pods linear, mostly i-nerved; seeds often wing-margined. ARABIS XIII. 



I. LEPIDIUM. Pepperwort or Peppergrass. 

 (Gr., lepidion, a little scale, with reference to the little pods.) 



Flowers white ; pods short, the boat-shaped valves or carpels flattened 

 contrary to the narrow partition ; pod 2-seeded and very flat. Stamens 

 sometimes fewer than 6, and petals sometimes wanting. 



