70 MUTATIONS, VARIATIONS, AND RELATIONSHIPS OF THE OENOTHERAS. 



OENOTHERA OAKESIANA (ROBBINS) S. WATSON. 



Oenothera biennis var. oakesiana Robbins. A. Gray, Man., ed. 5, 178, 1867. 

 Oenothera oakesiana S. Watson. Biblio. Ind. N. Am. bot., 383, 1878. 

 Onagra oakesiana Britton. Mem. Tor. bot. cl., 5: 233. 1894. 



Seedling about 2 months old. Leaves obscurely puberulent, with few scattered hairs; 

 blades oblong or oblong-obovate, 6 to 8 mm. wide, rounded or obtuse at the apex, tapering 

 to a slender margined petiole (plate 15, A). 



Seedling about 5 months old. Rosette crowded, symmetrical, 7 to 8 cm. in diameter; outer 

 leaves 3 to 4 cm. long, 8 to 10 mm. wide; blades oblong-ovate, broadest above the middle, 

 obtuse at the apex, tapering to the white, margined, entire petiole, dull or pale blue-green, 

 rather fleshy, approximately denticulate above, glabrous, except for a few obscure hairs on 

 the margins. 



Seedling 8 months old. Rosette 9 to 10 cm. in diameter, very symmetrical and crowded, 

 raised above the ground with a few of the old leaves adhering to the rootstock; blades approx- 

 imately and more prominently denticulate. 



Mature rosette. Leaves more or less strigose-pubescent all over, the central ones quite 

 densely so, the larger ones from 15 to 20 cm. long; blades narrowly lanceolate, approxi- 

 mately and shallowly toothed at the acute apex, more deeply toothed at the slender, taper- 

 ing base (plate 15, B). 



Adult plant. Plant i to 1.5 m. high, rather slender, clothed nearly throughout with a fine, 

 close, strigose, appressed, and somewhat cinereous pubescence and few scattering longer 

 spreading hairs, becoming almost glabrate and glaucous with age. Stem light or whitish 

 in color, angled and channeled above, branched to the middle; leaves 10 to 15 cm. long; 

 blades shallowly and remotely toothed, often more deeply so at base, narrowly lanceolate, 

 acute and tapering at each end, sessile or nearly so, gray-green and shining above, paler 

 beneath, rather thick and somewhat brittle ; terminal rosette-like cluster of the inflorescence 

 symmetrical, the floral bracts very small, divaricately spreading; bracts narrowly lanceolate, 

 more deeply and regularly toothed than the leaves, acuminate at the apex, tapering to the 

 base, sessile, becoming 2.5 times as long as the mature capsule; conic portion of bud 10 to 

 13 mm. long, rather prominently 4-angled, 4 to 5 mm. in diameter at the base, the free 

 separate divaricate tips 5 mm. long, finely but inconspicuously appressed pubescent; hypan- 

 thium 2.5 mm. to 2.7 mm. long, slender, finely but sparingly pubescent; calyx-lobes half as 

 long as hypanthium; petals firm, 13 to 15 mrn. long, 12 to 14 mm. wide, deeply emarginate, 

 not opening widely; filaments 12 mm. long; anthers 7 mm. long; pistil as long or slightly 

 shorter than the exserted stamens, the lobes erect, 4 to 5 mm. long; capsules 3 to 3.5 mm. 

 or more long, 7 to 9 mm. in diameter, angled and rounded, finely appressed-pubescent, 

 abruptly constricted near the apex. Remarkable for its large seeds (plates 16 and 17). 



Massachusetts. Uxbridge, J. W. Robbins, August, 1878. 



Rhode Island. Providence, E. P. Bicknell, August, 1896; September, 1899. 



New York. New York Botanical Garden, D. T. MacDougal, September, 1904; Cold 

 Spring Harbor, Long Island, G. H. Shull, September, 1904. 



The above specimens are the only ones in the herbaria of the New York 

 Botanical Garden and Columbia University that can with any degree of 

 certainty be referrred to O. oakesiana. The Robbins specimen is from the 

 herbarium of the late Rev. Thomas Morong and attached to its sheet is the 

 following note in the writing of its discoverer. 



