HYBRID DROSERA. 241 
OBSERVATIONS ON SOME HYBRIDS BETWEEN DROSERA 
FILIFORMIS AND D. INTERMEDIA.* 
By Prof. J. MurrHeap Macraruane, D.Sc., 
Professor in the University of Pennsylvania, U.S.A. 
ACCOMPANIED by a few of my students, an excursion was made, during 
the third week of June, to the rich botanising grounds near Atco, N.J. 
Amongst the pine-barren swamps of that locality was an area, several 
acres in extent, which was partially flooded, but clothed with a profuse 
surface vegetation of swamp or bog plants. These consisted almost 
entirely of the four species Hriocauion septangulare, Drosera intermedia, 
D. filiformis, and a yellow-flowered Utricularia. 
The later blooms of D. filiformis were still abundant, but the involute 
flower stalks of D. intermedia were just unrolling, and, as was proved 
later, these did not bloom fully till the second week of July. Casting 
one’s eye across the swampy mass of vegetation, the clusters of pale 
pink elongated leaves of D. jfiliformis contrasted strongly with the short 
dense clusters of crimson-pink leaves belonging to D. intermedia. 
After a considerable stretch of the marsh had been examined, my 
attention was arrested by a rather distant group of plants, somewhat 
intermediate in height and colour between the two common species around. 
A nearer examination of the eleven plants composing the group suggested 
the possibility of their being natural hybrids between the above-named 
species. They were carefully removed, without injury, to one of the 
greenhouses in the University Botanic Gardens, where they have since 
been grown and watched. A continued and careful exploration of the 
swamp failed to reveal the presence of additional plants or plant clusters 
like those already found. 
Detailed comparison of the leaves, flower stalks, inflorescence, flowers, 
and period of blooming still further confirmed the suspicion entertained 
on finding them. Histological investigation of the three, as well as of 
D. rotundifolia, which was only sparingly present in the marsh, shows 
that the last-named species does not contribute to the formation of the 
plants in question. It equally demonstrates a minute blending, in all 
parts of the hybrids, of the histological peculiarities of D. jiliformis and 
D. intermedia. 
When the eleven specimens were collected, care was taken to remove 
sods of both parent species, and all three were grown in neighbouring flats 
in the greenhouse. The parent species matured an abundance of what 
seemed to be good seeds. The contents of the hybrid pods were appa- 
rently useless. A detailed description of the macro- and micro-morphology 
of each will now be given under the following heads : (a) leaves, (b) axis 
of inflorescence, (c) inflorescence, (d) period of blooming, (2) size and 
colour of the blooms, (f) floral structure. 
* This note first appeared in the publications of the University of Pennsylvania, 
and was kindly sent over by Dr. Macfarlane to the Conference, with living specimens 
of the hybrid and its parents.—Eb. 
R 
