vm] Plants which cause Mechanical Injury 101 
Anthemis arvensis L. (Corn Chamomile). 
Anthemis Cotula L. (Stinking Mayweed). 
Artemisia Absinthium L. (Wormwood). 
Conium maculatum L. (Hemlock). 
r Hyoscyamus niger L. (Henbane). 
Matricaria Chamomilla L. (Wild Chamomile). 
Pinguicula vulgaris L. (Butterwort). 
Senebiera didyma Pers. (Lesser Wartcrestf). 
Sium angustifolium L. (Lesser Sium). 
Sium latifolium L. (Water Parsnip). 
Tanacetum vulgare Jj. (Tansy). 
Thlaspi arvense L. (Penny Cress). 
(See also Index "Milk, plants affecting," p. 117.) 
PLANTS WHICH CAUSE MECHANICAL INJURY. 
There are a number of plants which, while not necessarily physio- 
logical poisons, may induce injuries of a severe character when taken 
by animals, and by causing festering may bring about septic poisoning. 
For example the sharp pointed fruits of Stipa pinnata and Nardus stricta 
may cause injury to the skin and mouth, piercing the palate and causing 
inflammation, and when eaten may even perforate the wall of the 
intestine and cause death ; and the awned glumes of species of Bromus 
or the spikelets of Hordeum may injure the gums, causing inflammation, 
ulceration, sores, the formation of pus, and loss of teeth. The Bromus 
and Hordeum, also, together with over-matured "heads" of Trifolium 
incarnatum, may give rise to phytobezoars or balls in the stomach of 
horses and cattle (60, 119). The sharp pointed fruits of Erodium 
dcutarium may cause local irritation by working into the wool of sheep. 
Aira caespitosa may also cause injury to the mouth of stock. 
A case is recorded in New South Wales in which cattle and horses 
ate Shepherd's Purse (Capsella Bursa-pastoris). The cattle were 
unaffected, but the horses scoured, though most of them soon recovered 
when removed from the cultivated paddock containing the weed. Two 
young horses, however, showed signs of colic, became bloated, and 
died. It was then found that they contained balls of fibrous material 
(one weighed 1 Ib. 9| oz.) which consisted to the extent of nearly 50 per 
cent, of fibres from Shepherd's Purse, and death was due to simple 
mechanical obstruction of the bowel (155). 
Chickweed (Stellaria media) has been found to cause digestive disorder 
