1918] 
PAYSON—NOTES ON CERTAIN CRUCIFERAE 149 
This variety is named in honor of Mr. E. J. Palmer, from 
whose excellent Texan collections the type has been chosen. 
2. D. membranacea, n. sp.! 
Annual or biennial, green, rather sparsely pubescent with 
loose imperfect stellae or branching hairs; stems several from 
the root, sparingly branched, slender, decumbent, 3-6 dm. 
long; cauline leaves thin, narrowed abruptly at the base into a 
slender petiole about 1 em. long, blade 3-4 em. long, 2.5-3 em. 
broad, irregularly ovate or oblong in outline, toothed or un- 
dulately lobed, apex broad and rounded; basal leaves un- 
known; sepals spreading, purplish; petals white, orbicular to 
oblong, abruptly narrowed to a very short claw and then 
somewhat dilated to point of insertion, margin irregular; fila- 
ments scarcely broadened at base; fruiting inflorescence 
elongated, pedicels about 12 mm. long, slender, divergent; 
pods apparently yet immature, erect or ascending, pubescent 
with two quite distinct sizes of branched hairs, substipitate, 
reticulated, and apparently lacking the margin so conspicu- 
ous іп D. Wislizenit, cells nearly orbicular, about 4 mm. in 
diameter, replum about as long; style scarcely 1 mm. long, 
stigma subeapitate, slightly elongated over the middle of the 
carpels. 
Distribution: Tamaulipas, Mexico. 
Specimen examined: 
Mexico: vicinity of Victoria, Tamaulipas, alt. about 320 m., 
February 1—April 9, 1907, Dr. Edward Palmer 87 (Mo. Bot 
Gard. Herb.), TYPE. 
It is extremely interesting to find another species of 
Dithyrea very different from either of the two previously 
known. In general aspect it is much more like D. californica 
than D. Wislizenti, but in the characters of the flowers and 
fruit itis surely nearer the latter. The specific name was sug- 
1 Dithyrea membranacea, sp. nov. D. Wislizenti peraffinis sed caulibus 
foliisque viridibus parce pubescentibus; caulibus ety c decumbentibus 3- 6 
m. longis; foliis че ер membranaceis subovatis vel oblongo — eirca 3—4 
em. longis 2.5-3 em. latis plus minusve br таит) ге back in p iolum circa 
] em. longum abrupte Tem atis apice undatis; calycis дес pate enti bus pur- 
pureo- tinctis; corolla alba; siliquiis ад ica non (?) marginatis.—Collected 
in the vicinity of Victoria, Tamaulipas, February l-April 9, 1907, Paine 87 (Mo. 
Bot. Gard. Herb.), TYPE 
