pressed ; the outer valve completely conduplicate, with a sharp keel, the lateral form (being thus doubled) is
linear-oblong, with one nerve at the keel, and two very prominent ones on each side ; the apex rather acute,
the whole scabrous ; inner valve bifid at the point, prominently two-keeled at the back, the keels scabrous.
T a b . CCXXXII.—Fig. 1. Spikelet; ƒ. 2. Glumes ; f . 8. Floret:—magnified.
11. F. scabrella; panicula erecta, ramis patentibus, spiculis 3-4-floris teretibus minute
scabrellis, perianthii valvula exteriore 5-nervi in aristam perbrevem acuminata, interiore
apice bifida, marginibus inflexis ad flexuras nervosis, foliis plerisque radicalibus angusto-
linearibus ad vaginam cito deciduis. (T a b . CCXXXI1I.)—F . scabrella, Torr. M st.
Culrni pedales, erecti, ceespitosi, striati, subunifoliati, glabri; folio anguste lineari-acuminato vis duas uncias
longo, vagina longissima sub lente scabriuscula: reliqua folia etiam glabra, pleraque radicalia, membranaceo-
vaginata, angusto-linearia, 3-4 pollicaria, ad vaginas articulata, cito decidua. Panicula composita, 8-4 polli-
caris, erecta; rami patentes, versus apicem spicigeri. Spiculce viridi-purpurese, 3-plerumque 4-floree, ovatae,
f unciam longse, extus tactu vel sub lente minute scabrellte. Glumce incequales, acute, flosculis subduplo
breviores, enerves, muticse. Flosculi teretes; perianthii valvula exterior quinquenervis, in aristam perbrevem
sensim acuminata; interior lanceolata, plana, marginibus infiexis ad flexuras uninervibus scabris, apice bifida.
H ab. Alpine districts of the Rocky Mountains. Drummond.—This is a very distinct, and highly peculiar
species. There is seldom more than one leaf on the culm. The rest are radical, and have broad membranous
sheathing bases, from the top of which the blade of the leaf is very deciduous. The texture of the
florets is soft and membranaceous.
T a b . CCXXXIII.—Fig. 1. Spikelet; f . 2. Perianth :—magnified.
- 38. BROMUS. L.
1. B. purgans, L .—Rich, in Frankl. ls£ Journ. ed. 2. App. p. 3. Torr. FI. 1. p. 128.
This appears to me, judging from the specimens before me, to be a species that varies much according to
age and locality. In its more usual form the panicle and spikelets very much resemble our European B.
erect us; but the great breadth of the hairy leaves will at all times distinguish it. As has been already suggested
in the Botany of Capt. Beechey’s Voyage, p. 119., probably the B . pubescens of Muhl., the B. Canadensis,
Mich., the B. cilialus of Linn., and the B. purgans are all vars. of one and the same species. It will
be seen in the “ Floraof the Northern and Middle United States,” how doubtful Dr Torrey himself is about
those reputed species. The following are what I should enumerate as vars. In speaking of the hairiness
of the florets, I would be understood as alluding to the outer valve of the perianth : the inner is always beautifully
ciliated at the flexure of the margin.
«■ .vulgaris; panicula elongata laxa, spiculis angustis 6-8-floris viridibus, flosculis sericeo-villosis.—H ab.
Canada to the Saskatchawan. Goldie. Dr Richardson. Red River. Douglas. Columbia. Dr Scouler.—
subvar. a. flosculis glabris vel ad nervos tantum rarius ciliatis.—H ab. Fort Norman. Dr Richardson.
p>. pallidus ; panicula densa subcorymbosa, spiculis paullo latioribus magis compressis pallide virentibus 6-7-
floris, flosculis marginibus sericeo-villosis.—H ab. Saskatchawan to the Rocky Mountains. Drummond.
y. purpurascens ; panicula elongata laxiuscula, spiculis latioribus 6-8-floris viridi-purpurascentibus marginibus
prsecipue sericeo-villosis.—H a b . Bear Lake to the Arctic sea-coast. Dr Richardson.
2. longispicata; panicula densa subcorymbosa, spiculis latioribus biuncialibus viridi-purpurascentibus marginibus
preecipue sericeo-villosis.—H a b . Rocky Mountains. Drummond.
2. B. Sitchensis (Bong.); panicula patula (demum patente?) nutante, spiculis 5-7-floris,
flosculis lanceolatis setis terminalibus rectis valvula paullo brevioribus, ligula oblonga
producta. Bong. Veget. Sitcha, p. 55.
H ab. Sitcha. Mertens.—“ Maxime affinis Br. pendulino, Sesse, (Roem. et Sch. 2. p. 644,) cui et habitu
simillimus (nam radii inferiores longi, in speciminibus junioribus nostris patuli tantum, demum fOrtasse patentes);
differt potissimum setis, flosculorum longidribus, ligula magna rotundata (nec brevi truncata,) ut in Br. pendulino,
et foliis majoribus.” Bongard.
39. CERATOCHLOA. P. Beauv.
1. C. brevi-aristata; panicula elongata laxa subnutante, spiculis lanceolatis ancipiti-
compressis glabris (sub lente, scabris), glumis subineequalibus acutis submuticis nervosis,
perianthii valvula exteriore acute carinata multinervi brevi-aristata, foliis lato-linearibus
villosulis, vaginis villoso-tomentosis. (T ab. CCXXXIV.)
H a b . Dry elevated ground of Lewis’ and Clarke’s River, and near the sources of the Columbia. Douglas.
—Culm 2-3 feet high, near the base as thick as a swan’s quill. Leaves very broadly linear-acuminate, slightly
hairy. Ligule ovate, membranaceous, white. Panicle 8-10 inches long, slightly compound, erect, or a little
drooping to one side. Spikelets inclined (not drooping), an inch or an inch and a quarter long, lanceolate,
remarkably compressed, sharply 2-edged, of a harsh and rigid texture, of a pale uniform green colour, minutely
scabrous, more so on the keel. Glumes moderately unequal, lanceolate, acutely carinate, gradually coming
to a point, not aristate, shorter than the florets, outer about 5, inner about 9-nerved. Exterior valve of
the perianth complicato-compressed, sharply carinate, 9-or more nerved, having a very evident, but short,
straight awn, from between the slightly bifid points. Inner valve scarcely half so long as the outer, narrow,
lanceolate, bifid at tbe point, the margins sharply inflexed; at the flexures there is a strong ciliated green nerve.
Stamens 3. Filaments, apparently, in the advanced state of the flower, incorporated with the ovary-, for I can
in no instance trace them, till they become free at the top of the crest of the germen. Anthers (abortive ?)
small, ovate. Ovary and young fruit oblong with a deep furrow in the inner face, crowned with a 3-lobed
whitish hairy crest. Allied to Ceratochloa unioloides, Beauv. (which has been found in Texas by Mr Drummond,
No. 376, of his 3d Coll.) but very different in the foliage and in the presence of a distinct awn to the
florets.
T ab . CCXXXIV.—Fig. 1. Spikelet; f. 2. Glumes; f. 3. Perianth; f . 4. Outer view of an inner valve
of do.; f. 5. Immature fruit:—magnified.
2. C. grandiflora; panicula subsimplici laxa, spiculis valde compressis subancipitibus
pubescenti-scabris 10-11-floris, glumis subtequalibus acuminatis vix aristatis 9-nerviis car-
inatis, perianthii valvula exteriore compresso-carinata 9-nervi arista stricta valvulee dimi-
dio longitudinis terminata, foliis lanceolato-linearibus vaginisque hirsutulis. (Tab.
CCXXXV.)
H ab. Common on the plains of the Columbia. Dr Scouler. Douglas.—Allied to the last in its compressed
florets, but quite distinct. The spikelets are in some of the specimens much longer than in any species of the
genus I am acquainted with. Although the florets are carinated they are less so than in the preceding species,
and more remote on the rachis : the awn, too, is far longer than in that species. The inner valve is gradually
attenuated into a long acumen, deeply bifid at the point. In the flowering spikelets, the filaments may
easily be traced to the base of the ovary; but in a more advanced state, the lower part of the filaments pro