Bracken (Pteridi>um aquilinum), a perennial fern, is represented in the West 

 only in the variety pubescent. That variety, usually known as western bracken, 

 very closely resembles bracken, save for its fine, silky hairs, especially on the 

 under surfaces of the leaves (fronds). 



Western bracken is widely distributed, occurring in all the far Western 

 States and ranging from Alaska and British Columbia to Montana and south- 

 ward to Mexico and California. It probably grows in greatest abundance and 

 attains its maximum development in the Douglas fir regions west of the Cas- 

 cade Mountains of Washington and Oregon. It is also very abundant in parts 

 of Idaho and California. In altitude it ranges from near sea level in the Pacific 

 Northwest up to about 10,000 feet in Colorado. 



Western bracken grows in both moist and fairly dry sites, although it seems 

 to prefer deep, rich, moist soils. It occurs underneath stands of timber such 

 as Douglas iir r aspen, and ponderosa pine and grows in openings and parks 

 among the timbered and wooded areas throughout the western mountains. In 

 places in the Pacific Northwest it occurs in extensive dense patches on burns 

 and cut-over areas, which it quickly invades, and also in openings, and along 

 roadsides and field borders. When the bracken cover dries up during the late 

 summer and fall it often constitutes a very serious fire hazard. The plant 

 invades hay and other cultivated fields and often becomes a serious weed pest, 

 which is difficult to eradicate because of its nersisteut, wiry, and extensive 

 underground stems, a small portion of which, if left, can give rise to new plants. 



As range forage western bracken is usually considered worthless or of dis- 

 tinctly minor importance. Its palatability ordinarily ranges from zero to poor. 

 However, under some circumstances, particularly after frosts in the fall, it 

 is occasionally grazed with as much as fair relish by all classes of livestock. 



Lawrence 2 states that horses sometimes acquire a taste for it. When eaten 

 in quantity it is poisonous, at least to cattle and horses. He considers western 

 bracken to be the chief cause of livestock poisoning in western Oregon. He 

 further reports to the effect that, although the plant has been known since 

 pioneer days in western Oregon to be poisonous to horses, causing fern staggers, 

 there is very little good evidence that horses or other livestock are commonly 

 poisoned by this fern on the range or in the pasture. Losses of horses from 

 this disease are, rather, due to feeding them hay which contains about one- 

 third or more of western bracken. These losses are greater in dry seasons, 

 apparently due to shortage of good hay, and are heaviest following the haying 

 season, although, of course, ferny hay may be dangerous at any time of year. 



The poison responsible for fern staggers is in the leaves, or fronds, and is not 

 due to the so-called rust (masses of spores) found on the under sides of the 

 leaves. In many parts of the world the young fronds of bracken are boiled 

 and the rootstocks roasted for food. Such poisonous principles as the plant 

 possesses appear to be effectively dissipated by the application of heat. This 

 fern has special astringent properties and is said by some authors to have the 

 property of killing tapeworms. 



Western bracken reproduces by two methods, both of which are very effective. 

 As before-mentioned, the widely creeping underground stems (rootstocks, or 

 rhizomes) send up new leaves (fronds) at various places along their length. 

 Thus this fern is able to form dense patches over rather extensive areas. It 

 also reproduces by "seed" (spores), which are produced from July to September 

 in large, brown, powdery masses along the turned-under (revolute, or retrorse) 

 margins of the lower surfaces of the fronds. The individual spore is micro- 

 scopic in size, and so light that large numbers of them can be borne for great 

 distances by the wind. The young seedling plant, often established far from 

 its parent fern, begins very shortly to produce rootstocks of its own. 



The fern genus Pteridium, to which western bracken belongs, is included by 

 some botanists in the larger, Old World brake genus (Pteris). Bracken is a 

 widely distributed genus of six or eight species, three or four of which occur 

 in North America. 



s Lawrence, W. E. THE PRINCIPAL STOCK-POISONING PLANTS OF OREGON. Oreg. Agr. 

 Expt. Sta. Bull. 187, 42 pp., illus. 1922. 



