CRUCIATE-FLOWERED CENOTHERAS OF SUBGENUS ONAGRA 243 
Bethesda, Montgomery County, Maryland. Specimens from garden 
plants, Bartlett2']ij and 3146 (type, in U. S. Nat. Herb. nos. 693733-5.). 
Bureau of Plant Industry, 
Washington, D. C. 
Explanation of Plates XIX-XXI 
Plate XIX, Fig. i. Oenothera atrovirens Shull & Bartlett. Flowering plant. 
(The small label is 10 cm. long.) 
Fig. 2. Oenothera venosa Shull & Bartlett. Flowering plant. (The small label 
is 10 cm. long.) 
Plate XX. Oenothera atrovirens Shull & Bartlett. Inflorescence and details. 
Plate XXI. Oenothera venosa Shull & Bartlett. Inflorescence and details. . 
