Colorado Plants Injurious to Livestock 
27 
RUSSIAN THISTLE (Salsola pestifer) 
The Russian Thistle is so well known that a description is un¬ 
necessary. In Prof: Pammel’s Manual of Poisonous Plants is found 
the following: ‘‘The sharp spines on the plants not only irritate and 
worry both horses and men but often, by breaking under the skin, 
cause festering sores on the horses’ legs, so that in many localities it 
has been found necessary to protect them with high boots or leggings.” 
•COW-HERB, COW COCKLE, WHEAT COCKLE 
(Sap onaria vaccaria) 
A smooth, branching annual plant (fig. 19) 8 to 16 inches tall. 
The leaves are opposite and lance-shaped. The flowers are a beauth 
ful pink, in open clusters at the top of the plant. The calyx is 5- 
angled, and much enlarged in the fruit. The plant is a pest in some 
sections of the state, particularly in grain fields. It is found mostly 
at low altitudes. 
The seeds of Cow Cockle are often found in wheat screenings, 
and are known to be poisonous. Prof. Pammel says: “According to 
Sohn it contains the substance saponin, a neutral, sharp, amorphous 
substance, having a burning taste and producing a violent sensation. 
The toxic substance is partially removed by baking.” Saponin-like 
bodies are also found in the common plant known as “bouncing bet” 
and corn cockle. 
LARKSPUR (Delphinium) 
As a group, the larkspurs are easily recognized by the single 
long “spur” (figs. 20, 21, 22) of the flower. A single sepal of the 
flower is prolonged into a spur, and encloses two petals which are 
likewise extended. Larkspurs may be distinguished from aconite 
or monkshood, which they closely resemble, by the form of the flower. 
In aconite or monkshood the upper sepal, instead of being spurred, as 
in larkspur, is enlarged and has the appearance of a hood (fig. 23) 
over the other flower parts, hence the name monkshood. These dif¬ 
ferences are brought out in the drawings. 
A number of native plants are often mistaken for larkspur, espe¬ 
cially in the young stage. Chief of these is the wild geranium, of 
which there are several species within our borders. There are two 
small leaves (stipules) (fig. 30) at the base of the geranium leaf¬ 
stalk; these are absent in larkspur. The false mallow (fig. 31) 
(Malvastrum coccineum), when young, may also be mistaken for 
larkspur. Its leaves are coated with hairs that are in star-shaped 
groups (fig. 32). The leaves of the common spring anemone (fig. 
34) (Pulsatilla hirsutissima) with lavendar flowers, are much more 
divided and in a fashion different from those of larkspur. The wind 
flower (fig. 3J ) {Avenwne) has 1 aves quite similar in shape to those of 
larkspur but the hairs are longer and more spreading. Both the com¬ 
mon spring anemone and the wind flower have a characteristic group 
of leaves (involucre) on the flowering stem (see fig.36). In fig 35 
is shown the highly divided leaf of Virgin’s Rower (Clematis doug- 
lasii) which may be mistaken at times for that cyf one of the larkspurs. 
