764 



THE AMERICAN NATURALIST. [Vol. XXXVII. 



Oenothera lamarckiana Sen 



I. Seedling about two months 

 old. — Leaves sparingly pubescent ; 

 blades ovate to suborbicular, the 

 larger about 2 cm. wide, obtuse or 

 rounded at the apex, each abruptly 

 narrowed into a petiole. 



II. Seedlings 3 inoiiths old. — 

 Rosettes relatively dense : leaves 

 copiously fine-pubescent ; blades 

 typically oblong, the larger ones 

 fully 3 cm. wide, quite approxi- 

 mately denticulate, obtuse, or some- 

 what apiculate at the apex, much 

 longer than the petioles. 



III. Adult plant. ~V\-&x\X very 

 stout and luxuriant, 0.5 to i m. 

 tall. Stem markedly channeled, 

 sparingly hirsute with rather 

 spreading hairs, nearly simple, or 

 with several relatively short as- 

 cending branches near the base, 

 and few very short ones above : 

 leaves very numerous, 2-2.5 dm. 

 long about the base of the stem ; 

 blades shallowly and often irregu- 

 larly toothed, those of the lower 

 cauline leaves broadly spatulate to 

 oblong, rather acute, each nar- 

 rowed into a nearly semi-terete 

 petiole, those of the upper cau- 

 line leaves oblong to oblong lanceo- 

 late, acute, or somewhat acuminate, 

 short-petioled : bracts subcordate 

 at the base: hypanthium 4.5-5.5 

 cm. long, about 8 mm. wide at the 

 mouth, prominently ridged : sepals 

 4-5 cm. long, longer than the tu- 

 bular portion of the hypanthium, 

 the free tips 8-10 mm. long: pet- 

 als firm 4-5 cm. long, emarginate : 

 anthers 13-15 mm. long: stigmas 

 5-6.5 mm. long. (See Figs, i, 4, 

 7 and g.) 



Oenothera rubrinervis deVries. 



I . Seedlings about 2 months old. 

 — Leaves manifestly less pubes- 

 cent than those of Oe. Lamarck- 

 iana ; blades elliptic, the larger 

 ones about 1.5 cm. wide, acute or 

 acutish at the apex, each gradually 

 narrowed into a petiole. 



I I . Seedlings 5 months old. — 

 Rosettes lax : leaves less densely 

 pubescent than in Oe. Lamarck- 

 iana ; blades spatulate to elliptic- 

 spatulate or oblong-spatulate, the 

 larger ones about 2.5. cm. wide, 

 remotely denticulate, acute, or ab- 

 ruptly pointed at the apex, about 

 as long as the petioles or shorter. 



III. Adult plant. ~V\?cni rel- 

 atively stout, less luxuriant than 

 Oe. Lamarckiana. Stem scarcely 

 channeled, hirsute, with rather as- 

 cending hairs, typically branched 

 throughout, the branches near the 

 base elongated, decumbent, the up- 

 per ones gradually shorter : leaves 

 numerous ; blades less prominently 

 toothed than in Oe. Lamarckiana., 

 those of the lower cauline leaves 

 spatulate to broadly oblong, obtuse 

 or acutish, each narrowed into a 

 relatively long petiole, those of 

 the upper caviline leaves elliptic- 

 oblong to oblong or oblong-lanceo- 

 late, acuminate, short-petioled : 

 bracts rounded or round-truncate 

 at the base: hypanthium 5.5 to 6 

 cm. long, about 4 mm. wide at the 

 mouth, obscurely ridged : sepals 

 3.3 to 3.5 cm. long, shorter than 

 the tubular portion of the hypan- 

 thium, the free tips 5-6 mm. long : 

 petals tender, 3-3.5 cm. long, 

 notched: anthers 6-10 mm. long, 

 stigmas 7.5-10 mm. long. (See 

 Figs. 2, 5, 8 and 10.) 



