1907] MACDOUGAL—HYBRIDIZATION OF WILD PLANTS 57 
NATADACEAE.—T wo cases in Potamogeton. 
CyPERACEAE.—Twelve hybrids in Carex. 
JUNCACEAE.—One hybrid between Juncus effusus and J. pacificus. 
LittacEAE.—One hybrid between Calochortus Benthami and C. albus. 
ORCHIDACEAE.—One hybrid between Habenaria lacera and H. psycodes. 
JUGLANDACEAE.—Three hybrids of Hicoria pecan with H. minima, H. alba, 
and H. laciniosa; one hybrid between Juglans nigra and J. cinerea. 
SALICACEAE.—About twenty supposed hybrids of Salix are noted; two hybrids 
of Betula are also reported, viz., between B. pumila and B. lenta, and between 
B. populifolia and B. papyrifera. 
FaGacEAE.—Thirty-five oak hybrids have been reported, but one of these, Q. 
Rudkini, has been tested, as described above, with negative results. 
RaNuNCULACEAE.—A hybrid between Actaea alba and A. rubra; Clematis vior- 
noides is reported to be of a hybrid nature. 
CruciFERAE.—Roripa palustris is supposed to form natural hybrids with R. 
obtusa and R. sinuata. 
Pomacrar.—Malus Soulardi is taken to be a cross between M. coronarius and 
M. Malus by some workers. 
RosacEaE.—Geum strictum and G. canadense are supposed to form a hybrid. 
PAPILIONACEAE.—A hybrid between Baptisia australis and B. bracteata is 
reported. 
ANACARDIACEAE.—Rhus hirta is supposed to cross with R. glabra. 
RaamNacear.—Ceanothus Lobbianus is taken to be a hybrid between C. thyrsi- 
florus and C. dentatus; it is also supposed that C. thyrsiflorus hybridizes 
with C. papillosus and C. sorediatus. 
VioLacear.—A large number of hybrids of Viola have been reported. 
ONAGRACEAE.—Oenothera biennis and O. Oakesiana hybridize, the progeny of 
the first generation consisting of several types. 
Cacracear.—A hybrid is supposed to be formed between Opuntia julgida and 
O. spinosior. ; 
Cornacear.—Cornus Baileyi has been taken to be a hybrid between C. asperi- 
jolia and C. stolonijera. 
VERBENACEAE.—The evidence seems strong that Verbena canadensis and V. 
bracteosa, V. bracteosa and V. hastata, V. bracteosa and V. urticifolia, V. 
bracteosa and V. stricta, V. stricta and V. hastata, V. stricta and V. urtici- 
jolia, V. urticifolia and V. hastata, V. angustifolia and V. stricta, V. angustt- 
folia and V. bracteosa hybridize. 
ACANTHACEAE.—Ruellia ciliosa parviflora has been supposed to be the result of 
a cross between R. ciliosa and R. strepens. a 
LoBetiacear.— Lobelia syphilitica is supposed to hybridize with L. cardinals. 
CicHortaceAar.—Prenanthes Mainensis is taken to be a cross between Nabalus 
racemosus and N. trifoliatus. : 
Compositar.—Hybrids are reported in Eupatorium, Solidago, Aster, Bidens, 
and Helenium. 
