366 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 



the inflorescence 6 to 7 cm., lanceolate-oblong, 12 to 14 mm. wide, curvately narrowed 

 above but at last very acute, below narrowed by more rapid curves to a short, broad 

 petiole distinguishable even in the upper leaves, closely repand-denticulate, regu- 

 larly feather- veined, the midvein broad, in texture thick, somewhat succulent, the 

 surface densely cinereous-pubescent, blue green; summit of axis and commonly several 

 branches spicate, the young parts, including ovary and calyx, very canescent; whole 

 length of flower 4 to 4.5 cm. ; calyx segments on the point of spreading about 21 mm. 

 long, separating commonly in pairs, the appendage terminal, subulate, at maturity 

 fully 4 mm. long; petals triangular-obcordate, about 14 mm. long and 13 mm. wide, 

 in fading very rufous at base; capsule truncate- lanceolate in section, somewhat 

 curved, 3 cm. long, perhaps longer, tomentulose, also thickly beset with upwardly 

 appressed, falcate hairs, the recurved tips of the capsule segments 2-lobed. 



Type in the U. S. National Herbarium, no. 618797, collected along the St. Louis 

 division of the Chicago, Burlington, and Quincy Railroad, about 2 miles south of 

 Concord, Morgan County, Illinois, August 20, 1910, by E. S. Steele. 



Found in good quantity on prairie soil, which had once been cultivated, but not 

 for 30 years or more, yet had not recovered its original Silphium and Laciniaria flora. 

 Doubtless one of a number of true prairie plants, such as Monarda mollis and IMianthus 

 grosseserratus, which have the power of maintaining themselves on ground which has 

 been plowed and again left to itself. Oenothera biennis was much more abundant on 

 the same ground, probably also native. 



Oenothera canovirens in habit resembles 0. biennis, except that the branches are more 

 erect. The latter species, as met in the field, either in Illinois or around Washing- 

 ton, ia not "usually simple," as stated by the New Gray's Manual. The leaves of 

 0. canovirens differ from those of 0. biennis in number, position, size, form, texture, 

 indument, and color, and in fact they are unique in their characters. In indument 0. 

 canovirens is perhaps most resembled by Onagra strigosa Rydb., but except in flowers 

 and fruit there ia not much comparison even in this regard, while the low, stout habit 

 and unequal foliage lengths of the latter give it quite another manner. The narrowly 

 oblong tendency of the leaves in 0. canovirens is to be noted in contrast with familiar 

 species. In the field a marked difference was observed in the position of the stamens 

 of this plant after anthesis as compared with those of 0. biennis, but I seem not to have 

 made a note and the detail now escapes me. 



Oenothera parvifiora (?) L. Syst. Nat. ed. 10. 2: 998. 1759. 



Commonly bushy, 1 to 1.5 meters high, dividing at or moderately above the base 

 into long upcurved-ascending branches, these with short -branches near the summit 

 or undivided, the stems thinly appressed-puberulent and with rather copious longer 

 hairs, many of these clearly tuberculate at the base, the tubercles red or green, in- 

 clined to be longitudinally narrow; leaves numerous, lanceolate or oblong-lanceolate, 

 somewhat petiolate, the largest 12 to 13 cm. long and 16 to 20 mm. wide, reducible,' 

 however, to 9 cm. long and 14 mm. wide, acute and often more or less acuminate, 

 unevenly repand, either distinctly or feebly denticulate, in the dry state rather thin 

 and firm but with a suggestion of succulence when green, minutely strigose beneath 

 with longer hairs on the midvein, above glabrate; calyx tube slender, from under 3 to 

 4.5 cm. long; body of full-grown bud 7 to 8 mm. long; calyx tube and segments nearly 

 glabrous, some short stiff hairs near the summit, the segments separating singly; ap- 

 pendages pronouncedly infraterminal, rather horn-like, 1 to 4 mm. long; petals trian- 

 gular-obcordate, reaching perhaps 11 mm. long, in dried specimens often seeming 

 much smaller, a little narrower or broader than long, of a slightly greenish yellow; 

 infructescence in strong plants becoming 20 to 30 cm. long, often more or less panicu- 

 late at the base, very woody, the capsules moderately tapering from near the base, 

 the largest little exceeding 2 cm. long, glabrous, the excurved apices of the segments 

 often 2-lobed, the valves distinctly feather-veined. 



This species is very common in sandy or gravelly ground, found also on clay, in the 

 vicinity of Washington. The most robust growth seen was in a sandy field on the 



