48 Introduction to Botany. 



C^) 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. 



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



Aeabis XIII. 

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



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



Pods terete or turgid. 



(d) Pods elongated, often angled; valves 1-3-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. 



(^) Low-tufted herbs, often with stellate pubescence. Draba XII. 



(c) Pods obovoid or pear-shaped; valves i-nerved. Camelina XL 

 Pods terete or turgid. 



(a) Pods elongated, often angled; valves 1-3-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 1-3-nerved; style or beak short. 



Sisymbrium II. 

 (i) Pods elongated, tipped with a stout beak; valves 1-5-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, 



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



Cardamine V. 

 (d) Stems leafless below, from horizontal tuberous rootstocks. Dentaria VI. 



(c) 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., lepidio7i, 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-secded and very flat. Stamens 

 sometimes fewer than 6, and petals sometimes wanting. 



