Page 882 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

840 SECTION | XIV Poisonous Plants

VetBooks.ir TABLE 61.1 (Continued) Common Name Habitat Distribution

Species
Selenium Accumulators
A. albulus d Cibola milkvetch Salt-desert shrub Northwestern NM, AZ
A. beathiii c Beath’s milkvetch Badlands AZ, NV, UT
A. bisulcatus Two-grooved milkvetch Sagebrush MT, WY, ND, SD, CO,UT, NM
A. crotalariae d Rattle box milkvetch Desert AZ, CA
A. cutleri d
A. debequaeus d
A. eastwoodiae d Eastwood’s milkvetch Badlands Four Corners
A. flavus Yellow milkvetch Alkaline soils Colorado Plateau
A. grayii d Gray’s milkvetch Badlands WY, MT
A. moencoppenis Moenkopi milkvetch Badlands UT, AZ
A. nelsonianus d Alkaline flats WY
A. oocalycis d Sagebrush CO, NM
A. osterhouti Osterhout milkvetch Clay hills Grand Co., CO
A. pattersoni Patterson milkvetch Oakbrush Rocky Mountains
A. pectinatus Tine-leaved milkvetch Northern prairies MT, ND, WY, CO, KA
A. praelongus Stinking milkvetch Badlands Four Corners
A. racemosus Alkali milkvetch Badlands Plains states
A. sabolosus Cisco milkvetch Badlands Eastern UT
A. saurinus d Dinosaur milkvetch Badlands Eastern UT
A. sophoroides d Painted desert milkvetch AZ
A. toanus d Toano milkvetch Salt-desert shrub Great Basin
P/J, pinyon juniper.
a
Many varieties, especially of A. lentiginosus, A. mollissimus, and O. sericea, have been referred to as separate species in the past.
b
Also contains selenium.
c
Also contains nitro-toxins.
d
Minor species.
From Ralphs et al. (2003) and Welsh et al. (2007).
2. Biennial or short-lived perennial plants exhibit oppor- The seed bank in the soil supports these cycles. The
tunistic survival strategies by relying on both timely seeds have hard coats and remain viable for many years,
and adequate moisture for germination, growth, flow- thus providing an ecological advantage to exploit environ-
ering, and seed set. Seeds germinate in fall following mental conditions and maintain the “boom and bust” pop-
autumn rains, persist over winter, and flower in spring. ulation cycles (Ralphs et al., 2003). Livestock poisonings
If sufficient moisture is available, they will remain for follow these cycles, often in catastrophic proportions.
2 or 3 years until the next drought occurs (A. mollissi-
mus, A. lentiginosus, and A. pubentissimus).
3. Long-lived perennial plants exhibit a stress-tolerant sur- Toxicology
vival strategy. They have deep taproots that can access Locoweed poisoning was one of the first poisonous plant
deep stored water. They grow where moisture is more problems recognized by stockmen and reported as early
abundant and more regularly available. The plants flower as 1873. Extensive stock losses in the western United
and produce seed for many years following initial estab- States eventually led to the establishment of a field station
lishment, although they too may die out during extended in Hugo, Colorado, in 1905 to study the problem.
droughts (O. sericea and O. lambertii). Research from 1905 to 1907 determined that certain