-9- 
• 
'-grey color when ripe; the outer covering removed shows the seed in 
spiral form. The root system of the plant is small, giving it but a 
slight hold on the ground; it can be easily pulled at any time. 
When the plant dies in the fall the wind may turn it out entire, or 
>eak it off at the surface. It is then ready to travel where the 
; 'nds may take it, distributing its seed as it goes. For further and 
re minute details of structure, the following technical description 
' >'n by Mr. L. H. Dewey, in bulletin No. 15, from the Division of 
* tny of the U. S. Department -of Agriculture, may be consulted : 
Technical Description. — Salsola kali tragus ( L.) Moq. in DC. Prod., XIII., 
,j l:2r ,i i- k (1849). A herbaceous annual, diffusely branching from the base, 0.5 to 1 m, 
(i>2 to 3 feet) high and twice as broad, smooth or slightly puberulent ; tap root 
dull white, slightly twisted near the crown ; leaves alternate, sessile ; those of 
the young plant deciduous, succulent, linear or subterete, 3 to 6 cm. (1 to 2 
inches) long, spine-pointed and with narrow, denticulate, membranaceous mar¬ 
gins near the base ; leaves of the mature plant persistent, each subtending two 
leaf-like bracts and a flower at intervals of 2 to 10 mm. (about one-twelfth to 
five-twelfths of an inch), rigid, narrowly ovate, often denticulate near the base* 
spine-pointed, usually striped with red like the branches, 6 to 10 mm. (three- 
twelfths to five-twelfths of an inch) long ; bracts divergent, like the leaves of the 
mature plant in size and form ; flowers solitary and sessile, perfect, apetalous, 
about 10 mm. (five-twelfths of an inch) in diameter ; calyx membranaceous, per¬ 
sistent. inclosing the depressed fruit, usually rose-colored, gamosepalous, cleft 
nearly to the base into five unequal divisions about 4 mm. (one-sixth of an inch) 
long, the upper one broadest, bearing on each margin near the base a minute 
tuft of very slender coiled hairs, the two nearest the subtending leaf next in size, 
and the lateral ones narrow, each with a beak-like connivent apex, and bearing 
midway on the back a membranaceous, striate, erose-margined horizontal wing 
about 2 mm. (one-twelfth of an inch) long, the upper and two lower wings much 
broader than the lateral ones ; stamens 5, about equaling the calyx lobes ; pistil 
simple *, styles 2, slender, about 1 mm. (one twenty-fifth of an inch) in diameter, 
dull gray or green, exalbuminous, the thin seed coat closely covering the spirally- 
coiled embryo; embryo, green, slender, about 12 mm. (one half inch) long when 
uncoiled, with two linear subterete cotyledons. The plant flowers in July or 
August and the seeds mature in Septemberknd October. At maturity the action 
of the wind causes the root to break with a somewhat spiral fracture at the sur¬ 
face of the frozen ground, and the plant is blown about as a tumble-weed. The 
mature flower with the inclosed seed is held in place in the axils of the bracts by 
the two minute tufts of coiled hairs, preventing the seeds from falling all at once 
when the plant begins to roll. . , „ . ^ 7 . , 7 . . 
The variety tragus differs from the typical form of Salsola kali, which is 
common along the Atlantic coast, in the following characters : The leaves of the 
mature plant are very little longer than the leaf-like bracts which they subtend, 
while in the typical form of the species they are generally two to four times as 
lone The calyx is membranaceous and nearly always bright rose-colored, and 
the” wings on the backs of the calyx lobes are much larger than the ascending 
lobes, while in the typical form the calyx is coriaceous and usually dull white or 
only slightly rose-colored, and the wings are thick, comparatively narrow, and 
less prominent than the ascending lobes. The species itself is less bushy in ha it 
and less rigid at maturity. It has been known along the Atlantic coast from 
Massachusetts to Georgia for nearly a century, and has never developed into a 
troublesome weed.”^ 
Three uf our native weeds have been mistaken for Russian 
thistle. These plants do, in some degree, resemble the thistle, but 
the leaf and spine characters of the latter can hardly fail to readily 
separate it from the others. The plant bearing the strongest resem¬ 
blance is the common tumble-weed, Amaranthus albus L. [Plate V.] ; 
its habit of growth is much the same, but its flat lea\cs, which may 
