XXXI. Papaveraceae. Poppy Family

Herbs with milky or coloured juice, narcotic or acid; leaves alternate without stipules; flowers regular with the parts in twos or fours, fugacious sepals, polyandrous; fruit a dry pod with numerous seeds.

I. Papaver. (Tourn.) L.

1. P. alpinum. L. Arctic Poppy.

XXXII. Fumariaceae. Fumitory Family

Delicate smooth herbs with watery juice; leaves compound, dissected, usually alternate; flowers irregular, with four somewhat united petals, the outer with spreading tips, and one or both of them spurred or saccate at the base, the inner pair narrower, their callous-crested tips united over the stigma; fruit a pod containing one or more seeds.

I. Dicentra. Benth.

1. D. formosa. DC. Wild Bleeding-heart. 2. D. uniflora. Kell. One-flowered Bleeding-heart. II. Corydalis. (Dill.) Medic.

1. C. aurea. Willd. Golden Corydalis.

XXXIII. Cruciferae. Mustard Family

Herbs with pungent watery juice; leaves alternate; flowers cruciform, tetradynamous, regular, in terminal racemes or corymbs; fruit a silique or silicle, sometimes nut-like, the pods and seeds give the chief character of the genera.

Tribe Alysseae

I. Draba. (Dill.) L.

1. D. incana. L. White Whitlow Grass.

2. D. lonchocarpa. Rydb. Long-podded Whitlow Grass.

3. D. prsealta. Spring Whitlozv Grass.

4. D. aurea. Vahl. Golden Whitlow Grass.

5. D. alpina. L. Alpine Whitlow Grass.

6. D. nivalis. Liljb. Arctic Whitlow Grass.

7. D. glacialis. Adams. Pale Yellow Whitlow Grass.

Tribe Physarieae

II. Physaria. Gray.

1. P. didymocarpa. (Hook.) Gray. Bladder-pod.

Tribe Lepidieae

III. Thlaspi. (Tourn.) L.

1. T. arvense. L. Penny Cress. (Introduced.)

IV. Lepidium. (Tourn.) L.

1. L. apetalum. Willd. Pepper Grass.

Tribe Camelineae

V. Capsella. Medic.

1. C. Bursa-pastoris. (L.) Medic. Shepherd's Purse. (Introduced.)

VI. Neslia. Desv.

1. N. paniculata. (L.) Desv. Neslia. (Introduced.)

Tribe Brassiceae

VII. Brassica. (Tourn.) L.

1. B. Sinapistrum. Boiss. Herb of St. Barbara. (Introduced.)

Tribe Sisymbrieae

VIII. Sisymbrium. (Tourn.) L.

1. S. Hartwegianum. Fourn. Hartweg's Tansy Mustard.

2. S. altissimum. L. Tall Hedge Mustard. (Introduced.)

3. S. canescens. Nutt. Pale Tansy Mustard.

4. S. incisum. Engelm. Western Tansy Mustard. IX. Braya. Sternb. and Hoppe.

1. B. humilis. (Mey.) Robinson. Northern Rock Cress. X. Erysimum. (Tourn.) L.

1. E. parviflorum. Nutt. Treacle Mustard.

Tribe Arabideae

XI. Radicula. (Dill.) Hill.

1. R. Nasturtium-aquaticum. (L.) Britten and Rendle. Water Cress. (Introduced.) XII. Cardamine. (Tourn.) L.

1. C. pennsylvanica. Muhl. White Bitter Cress.

2. C. bellidifolia. L. Alpine Bitter Cress. XIII. Arabis. L.

1. A. Holbcellii. Hornem. Stony Rock Cress.

2. A. hirsuta. (L.) Scop. Hairy Rock Cress.

3. A. Drummondii. Gray. Drummond's Rock Cress.

4. A. glabra. (L.) Benth. Smooth Rock Cress.

5. A. Lyallii. Wats. Lyall's Rock Cress.