172 
the other characters cited above. Collected at Exeter, Nebraska, 
by Rev. J. H. Wibbe. 
POLYGONUM EXSERTUM N. sp. 
Annual or perennial (?) slender, glabrous, sometimes somewhat 
glaucescent, of a light or dark brownish color. Stem erect or 
nearly so, 4-9 dm. tall, flexuous, rather conspicuously ribbed, 
branched above or throughout; branches slender and quite erect; 
leaves narrowly or linear-lanceolate, sometimes obovate, 1-6 cm. 
long, .2—.7 cm. broad, acute or cuspidate, acuminate at the base, 
nearly sessile ; ocrez several-parted when young, soon much lacer- 
ate, silvery or brownish, especially about the base; inflorescence 
consisting of axillary clusters bearing from 2 to 4 flowers; calyx 
greenish, but small and inconspicuous, 6-parted to near the base; — 
segments oblong, obtuse; stamens 5 or 6, included; style 3-cleft, 
very short or the stigmas almost sessile ; achene triquetrous, 4 
mm. long, narrow, triangular-pyramidal, rounded at the base, 
more or less constricted above the middle, chestnut color, smooth — 
and shining, exceeding the calyx by % to % of its length and — 
slightly spirally twisted when mature. (Plate 195.) Gs 
Sandy banks of Spirit Lake (Geyer, Nicollet’s Northwestern 
Expedition, No. 138), south to Valentine, Nebraska (Bates), east 
to St. Louis, Missouri (Engelmann), also at Providence and Bat- 
rington, Rhode Island (Olney), and York Harbor, Maine (Bicknell). ig 
The species here described has passed through an interesting | se 
history. Botanists under whose notice the plant has come have — 
either left it undetermined or have given it a name with more OF 
less doubt. It was apparently first collected by Chas. A. GeyeT — : 
at the source (Spirit Lake) of the Little Sioux River,on September 
30, 1839. No name was assigned to this specimen. The next 
collection was made by Engelmann at St. Louis, in September, 
1845, on both banks of the Mississippi River. These specimens — 
were labeled P. ramosissimum with some doubt. Later, in 1850, 
Mr. Olney found the plant at two localities in Rhode Island, 
namely: Providence and Barrington. He, like Engelmann, called 
them P. ramosissimum with more or less doubt. The last colle 
tions were by J. M. Bates at Valentine, Nebraska, in 1891, and by ae 
E. P. Bicknell at York Harbor, Maine. The most curious thing 
about the species is this: It has the general habit and aspect of P. 
ramosissimum and the inflorescence and fruit of P. Rayi. Its? 
semblance to the latter is so strong that for some time | 
