ItOSEANTIII'S. A NEW GENUS OF CUCURBITACE^ FKOM
ACAPULCO, MEXICO.
By Alfred Cogniaiix, Verviers, Belgium.
Roseanthus Cogn,, gen. nov.
Flores monoici
' omues axillares, solitarii. Masculi rares, longe pedieellati. Calycis
tubus longe tubulosus, angustus, superne leviter dilatatus; lobi 5, breviusculi, tri-
angulari-lineares. Corolla auguste canipanulata, usque ultra medium 5-lida, seg-
mentis integris oblongis acutis. Stamina 3. supra medium tubi calycis inserta,
filamentis liberie, elongatis, capillaribus; antherio in capitulum connata), una uni-
locularis caetera* biloculares, loculis linearibns longitudinaliter triplicatis, connec-
tive angusto noii producto. Pollen subsplnericum, subtiliter sparseque niuriculatum,
Pistillodium nullum. Flores feminei: Calyx supra ovarium et corolla maris. Stam-
inodia nulla. ( Karium anguste ovoideum, i-5-plaeentiferuni, multilocellatum, locel-
lis uniovulatis, oviilis horizontalibus; stylus eapillaris, elongatus, disco baailari
nullo, stigmatibus 3 elongatis profunde bifidis, lobis divaricatis. Fructus siccus,
indehiscens, multilocellatus, locellis monospermis longitudinaliter 4-5-seriatis, peri-
carpio tenui. Semina late ovata, lsevia, valde complauata, niarginibus subalatis
integerrimis,
1 lerbie anniue, scandentes. Folia petiolata, membranacea. Cirrbi 2-3-fidi.'2 Flores
inajusculi, albi, Fructus mediocris, globusus, Levis.
This genus belongs to the series Plagiospermeie. It is near Cucurbita, but differs
in the color of the flowers, shape of calyx, insertion of stamens, and absence of
Btaminodia.
Perhaps, however, it should be placed by the side of Schizocarpum, from which it
differs chiefly in its dioecious flowers, the absence of pistillodia, the three bifid
stigmas, and the indehiscent fruit.
I dedicate this new genus to Dr. J. N. Rose, the First Assistant Botanist of the
United States Department of Agriculture, in Washington, who has recognized its
characters and affinities, and to whom I am moreover indebted for specimens of
various new Cucurbitacea* and Melastomace;e.
1 1 have taken the liberty of changing Professor Cogniaux's dioici to monoicL The
first set of plants grown contained one specimen which produced male flowers only,
while all the others produced female flowers in abundance. It was a part of these
plants that were sent to Professor Cogniaux. Since then I have grown two other
plants, which for three or four weeks have been producing many female ilowers
but no male Ilowers. At length, however, male ilowers have begun to appear.
J. X. R.
*The tendrils have a curious habit when running over other plants (as for instance
the tomato) of forming small disks, by which they adhere. These disks not only
occur at the end of the tendrils, but also at a considerable distance back from the
tip.—J. N. R.
577
578
i
Roseanthus albiflorus, sp. nov. Plate XXVIII,
Slender vines, 9 to 12 dm. long, angled, pubescent: leaves ovate in outline, 3-lobed;
middle lobe ovate, acuminate, constricted near its base, with small apiculate teeth,
base with a broad open sinus: peduncle of male dowers 5 to 7.5 cm. long, of female
ilowers 4 to 6 mm. long: corolla 5 to 6 cm. broad : fruit the size of a small orange.
Collected by Dr. Edward Palmer in fruit near Acapulco, Mexico, March, 1895
(No. 599).
Flowering specimens were raised by J. N. Rose from seed in the greenhouses of the
United States Department of Agriculture at Washington.
Explanation of' Plate.—Fig. 1, a branch of the male plant; fig. 2, a branch of the female plant;
tig. II, the male flower laid open ; fig. 4, the pistil ; fig. 5, the fruit ; fig. 6, the seed.