Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 7, Pt. 4

BOTANY.
OxYBAPrHUS GLABRIFOLIUS, Vahl, Enum. 2, p. 40; var. crassifolius, Moq. in DC. Prodr. 1. c.
Santa Barbara; February. Stems numerous, from a woody base (as in O. angustifolia and in
some other North American species). Involucre 1-flowered, 5-cleft; segments triangular ovate, acute. Periantlh campanulate-rotate. Stamens 5, exserted.
ABRONIA ARENARIA, Lienz. in Hook. Exot. Fl. t. 193; Xoquin'it DC. Prodr. 13, pars 2, p.
435. San Louis Obispo; January.
ABRONIA MELLIFERA, Dougl. in Hook. Bot. Mag. t. 2879; Moq. 1. c. On the Gila river and in
the California desert; May to June.
POLYGONUM AcRE, H. B. K.; Gray, Manual ed. 2, p. 373. P. punctatum. Ell. Sk. 1, p. 455.
Salinas valley; November.
RUMEX MARITIMUS, Linn. Pursh. Fl. 1, p. 248; Hiook. Fl. Bor..Am. 2, ]. 130. Banks of the
Salinas river; November. A common plant in Oregon.
CHORIZANTHE (PTILOSEPALA) FIMBRIATA, Nutt. in P,. Gamb. (Journ. Acad. Sc. Philad., [n. ser.]
1, p. 168.) Torr. in Williamson's Rep. t. 8. San Diego, in sandy soils; April.
CRORIZANTHE (PTILOSEPALA) LACINIATA, (n. sp.): annual, erect; leaves all spatulate; scape
trichotomously branched; segments of the involucre about half as long as the tube; sepals
triangular acute, deeply cut into filiform segments. San Felipe; May. Very much like C.
fimbriata, but in the latter the spine-like seg,ments of the involucre are nearly as long as the
tube, and the sepals are oblong and obtuse. Both are remarkably prone to separate at the joints
of the scape.
ERIOGONUM ANGULOSUM, Benth. Eriog. in Linn. Trans. 17, p. 406, t. 18, fig. 1. San Filipe;
May. The exterior sepals are nearly orbicular, remarkably concave, and one-half shorter than
the interior ones. All of them glandularly ciliolate on the margin. Ovary and achenium
glabrous. Embryo curved, with a long radicle. Allied to E. Abertianum, Torr.
ERIOGONUM TRICHOPODITM, Tower. in Entory'8 Report, p. 150 (incorrectly E. trichopes); Bent.
in D. C. Prodr. 14, pars 1, p. 20. Sauz valley; August. The leaves are in a radical cluster,
roundislh-ovate, very obtuse, mostly cordate, entire or obscurely repand, somewhat hairy on both
sides; the petioles are nearly twice as long as the lamina. Peduncles capillary, 4-8 lines long,
spreading horizontally, or somewhat refracted. Involucre turbinate-infundibuliforin, obtusely
4-toothed, about 5-flowered. Bracteoles linear-spatulate, shorter than the pedicel. Achenium
triquetrous, glabrous.' This species is rather common on the Gila and lower Colorado. The
specimens collected by Dr. Antisell are nearly two feet high.
ERIOGONUM NUDUM, Dougl.; Benth. 1. c. Plentiful on the head-waters of San Antonio river,
California; December.
ERIOGONUM POLIFOLIUM, Bent7. in herb Torr., and in DC. Prodr. 14, (ined.) San Louis Rey
to San Diego; also in Santa Clara valley; February to April. A low shrubby species near E.
fasciculatum. It is variable in pubescence, being sometimes almost smooth.
CENTROSTEGIA, Gray, Nov.. Gen.
" Involucrum papyraceum, (demum coriaceum,) 1-2 florum, tubulosum, venosum, apice inequa liter 5-dentatum; dentibus mucronato-aristulatis, basim juxta tricalcaratum, calcaribus magnis,
divaricatis, breviter subulato-aristatis. Perigonium 6-partitium, petaloideum; laciniis tenuibus,
lineari-spathulatis, ungue hirsutulo. Stamina 9. Ovarium trigonum; styli 3, graciles; stig matibus capitatis. Achenium triquetrum. Embryo curvatum. Herba annua, demissa, glabra,
- a basi ramosa; ramis diffusis, floriferis flexuosis; foliis radicalibus spathulatis; ramealibus
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