1915] Bartlett,—Systematic Studies on Oenothera,— V 41 
SYSTEMATIC STUDIES ON OENOTHERA,— V. 
OE. ROBINSONII AND OE. CLEISTANTHA, SPP. NOVV. 
Harvey Harris BARTLETT. 
(Plate 111.) 
Ir has been shown ! that “ Oenothera cruciata” of the Manuals is an 
aggregate of genetically unrelated elements with little morphological 
similarity aside from their linear petals. A number of these elements 
have been separately defined, namely, Oe. cruciata Nutt., Oc. venosa 
Shull & Bartlett, Oe. atrovirens Shull & Bartlett, and Oe. stenomeres 
Bartlett. Moreover, Bicknell ? has described a cruciate-flowered ally 
of Oc. Oakesiana, Oe. stenopetala Bicknell, thus greatly strengthening 
the evidence that the character of cruciateness has originated inde- 
pendently in several lines of descent. 
In this article two more cruciate species are proposed, Oe. Robinsonii 
and Oe. cleistantha. The former has figured somewhat in genetical 
literature as an “elementary species of Oe. cruciata.” It was originally 
collected by Robinson in 1902 at Jaffrey, New Hampshire, and sent to 
de Vries. For several years prior to 1913 the strain had been lost 
from the experiment gardens, but Dr. Robinson very kindly collected 
it again at Jaffrey and sent seeds to the writer. These were planted 
last year, and gave a uniform culture of very slender-flowered plants 
which agree with all that we know of the strain originally cultivated 
by de Vries. 
There has been some confusion in the literature between Oe. Robin- 
soni and a form described by MacDougal which originated from seeds 
collected at Hudson Falls (Sandy Hills), New York, the type locality 
of Oe. venosa and Oe. atrovirens. Since my former article on the 
cruciate forms (l. c.) was published, I have received numerous seed 
collections from Mr. Stewart Henry Burnham, of Hudson Falls, which 
may make it possible to clear up this confusion as well as to determine 
whether Oe. venosa and Oe. atrovirens respectively are more closely 
1 Bartlett, H. H. An account of the cruciate-flowered Oenotheras of the subgenus 
Onagra. Am. Journ. Bot. I (1914) pp. 226-243. 
2 Bicknell, E. P. The ferns and flowering plants of Nantucket — XII. Bull. Torr. 
Bot. Club, XLI (1914) pp. 71-87. 
