410 DESCRIPTIONS OF NEW SPECIES 
tracted, five to eight or ten-flowered, the pedicels and involuerum bracteolate; sepals linear, acute, 
about twenty, often with dark purple sphaceolous points. Rays about eight. Pappus shorter than 
the lorets ; achenium smooth. Considerably allied to §, pratensis, but nearly smooth, also 
_ to the S. papposum. ‘There is a specimen very similar to our plant from Altai, sent to Dr. Schwei- 
nitz, but without any certain name. 
Fo Senecio * megacephalus; 2, stem low, densely lanuginous at base; leaves de- 
ciduously lanuginous, oblong-lanceolate, entire, cauline amplexicaule, linear- 
lanceolate, acute; corymb of three to five bracteolate, large capituli; involu- 
crum pubescent, of twenty to twenty-four linear, acute sepals, tipped with tufts 
of hairs; rays pale yellow, ten to twelve, scarcely as long as the involucrum; 
achenium smooth, with about ten striatures; dentures of the florets papillose. 
Has. On the plains of the Platte, towards the Rocky Mountains. Nearly allied to S. alpestris. 
About six to eight inches high; the leaves perfectly entire, more or less pubescent beneath, lower 
leaves with long petioles, Capituli very large, for the size of the plant, about as large as those 
of the common bur, (.4rctiwm lappa.) 
Senecio * fastigiatus; 2%, nearly smooth, or somewhat arachnoidly tomentose ; 
stem erect, simple, grooved, the summit compoundly corymbose and fastigiate ; 
leaves lanceolate or linear-lanceolate, entire or distantly serrulate, acute, the 
radical long petiolate, cauline few, sessile, linear, attenuated below, the upper- 
most amplexicaule; branches of the corymb two or three-flowered, pedicels 
elongated, bracteolate; involucrum turbinate, nearly naked, sepals twelve to 
fifteen; rays oblong, nearly entire, about eight, longer than the involucrum; 
achenium smooth. 
Has. The plains of Oregon, near the Wahlamet. A tall, rather slender species, two to three 
or more feet high, with a running root. Lower leaves with their petioles more than a span long, 
not more than half to three quarters of an inch wide. Leaves of the stem very small and distant, 
giving the plant a remarkably naked appearance. Sepals yellowish, linear, and acuminate. Rays 
long, (often twice as long as the involucrum,) few, and bright yellow, linear-oblong, slightly 
toothed, attenuated below, and sometimes tubular. Tubular florets, about twenty, the teeth ovate, 
aente, nearly smooth, exserted beyond the pappus. A few irregular slender bractes beneath the 
involucram. 2 
Senecio *exaltatus; 2%, more or less hirsute with white hairs; the radical 
leaves nearly smooth; stem tall, robust, nearly oe and grooved; lower 
leaves ee scsi: uneque 
long petiolate; bla es leaves small and eae ay aed sometimes 
deeply serrate; co: 
