Water Hemlock  Cicuta maculata Native Perennial  Poisonous  Family: Apiaceae Plant Attributes •Cool season forb •Adapted to moist locations •Roots tuberous, exceptionally poisonous •Toxin: Cicutoxin and cicutol •Causes muscle spasms, dilated pupils, dizziness, stomach pain, convulsions •Very small amounts can cause death Water hemlocks and the polyacetylenes they contain are not distasteful, thus contributing to their ingestion by animals and humans. In fact, it is reported that roots have a sweetish pleasant taste and pleasant order contributing to their acceptability (Mitchell and Routledge, 1978; Schep et al., 2009). Cattle readily eat new growth water hemlock in the early spring, often without death losses unless tubers or excess quantities of vegetative material are ingested (K.E. Panter, personal observation).” “It is well understood that water hemlock tubers are highly toxic to animals and to humans. However, this is the first time that immature seed from (Cicuta maculata) has been implicated in livestock poisoning. Nine mature Hereford cows from a herd of 81 died in northwestern Utah after ingesting immature seed heads of water hemlock (Cicuta maculata) in late summer.”   Drought / Stress Tolerance •Shade intolerant •Drought intolerant Grazing Tolerance •One of the most toxic plants in North America •Cattle especially at risk in comparison to all livestock (roots easily pulled up) Fire Tolerance •Topkilled by fire

Poison hemlock  Conium maculatum poisonous  Family: Apiaceae  Introduced perennial The juice or the extract of Conium maculatum was allegedly administered to criminals, and was the lethal poison, which the Greek philosopher Socrates was condemned to drink (399 BC.)   Hollow stem with distinctive purple spots   Plant Attributes •Cool season forb •Highest concentration of poison is in the seeds •Human deaths by confusing plant with wild carrot or parsnip •Affects the central nervous system causing muscle paralysis and respiratory failure •Sheep less affected than other livestock (horses, cattle) Drought / Stress Tolerance •Tolerates drier conditions than Cicuta maculata Grazing Tolerance •Highly poisonous to livestock •All parts of the plant are highly toxic Fire Tolerance •Topkilled by fire

Wooly Loco  Astragalus mollissimus Poisonous  Native perennial  Family: fabaceae  Plant Attributes •Cool season forb •Deep root development •Early season development (one of first green in spring) •Produces an addictive alkaloid (swainsonine) Forage Quality, Palatability, and Cover •Highly poisonous to livestock •Unpalatable to livestock, but once consumed in small amounts, animals will seek it out (especially horses) •Toxic effects accumulative •Causes weight loss, rough hair coat, disorientation, and anxiety •Affects optic nerves causing horses to shy violently, being difficult to back and bump into objects Drought / Stress Tolerance •Drought tolerant Grazing Tolerance •Toxic to livestock and wildlife

death camas  Zygadenus paniculatus Family: liliaceae  Poisonous  Native Perennial  Plant Attributes •Cool season forb •Early growth in the spring when other forages are not available •Bulbs have been mistaken for edible Allium (wild onion) Forage Quality, Palatability, and Cover •Toxic to animals at all times of the year •Unpalatable •Sheep most commonly poisoned Drought / Stress Tolerance •Drought tolerant Grazing Tolerance •Increaser with high intensity grazing

low larkspur Delphinium bicolor Family: Ranunculaceae Poisonous  Native Perennial Plant Attributes •Cool season forb •Extensively branched fibrous root system •Begins growth as soon as the snow comes off •Flowers from June to July Forage Quality, Palatability, and Cover •Utilized by elk, mule deer, pronghorn, birds and small mammals •Very poisonous to cattle •Fair cover for small mammals and upland birds Drought / Stress Tolerance •Full sun •Disturbance tolerance Grazing Tolerance •Increaser in response to grazing Fire Tolerance •Killed by fire

poisonous Halogeton  Halogeton glomeratus Introduced annual  family: Chenopodiaceae Distribution: Rocky Mountain and Great Basin region. Introduced from Russia and NW China Inflorescence • Flowers in the leaf axis Leaves succulent, cylindrical, and hair tipped Branched from the base Single taproot (annual plant) Leaves succulent, yellowish stems (pink upon maturation). Plant Attributes •Warm season forb •Poor root development in spring causes it to be less competitive. It does best in saline sites where competition is naturally low •High seed production •Produces black seed (no dormancy) and brown seed (high dormancy – 10 years) •Distributed by animals (sheep), tumbling (wind), and machinery •Early succession that can change plant communitiesHalogeton glomeratus - Autecology Forage Quality, Palatability, and Cover •Poisonous species (high in oxalates) – health threat to grazing animals (especially sheep) •Extremely low palatability, seldom eaten by livestock •Fair forage for small mammals and birds. •Provides poor protection for ungulates, but fair cover for small mammals and birds •Best control method is increasing perennial plants in the standHalogeton glomeratus - Autecology Drought / Stress Tolerance •Drought tolerant •Alkalinity tolerant Grazing Tolerance •Not readily grazed. •Invader.

poisonous  gray horsebrush Tetradymia canescens family: Asteraceae  Native Perennial  Distribution: Western U.S., western Canada Plant Communities: grasslands, sagebrush, desert shrub, PJ, chaparral, forests Soil Types: medium to coarse soils (prefers gravelly soil or sandy loams) Location: slopes, ridgetops, hills, plains at 1,300 to 10,800 ft. elevation' • Inflorescence • Heads 5-20 • 4 phyllaries (bracts under flower head) • Leaves • Alternate, simple with woolly surfaces • Prominent midvein • Stems gray in color • Bark shreddy Important Tetradymia canescens – IdentificationFlickr “Tetradymia canescens” images courtesy of Matt Lavin. Characteristic Growth FormFlickr “Tetradymia canescens” images courtesy of Matt Lavin. Characteristic Growth Form■ Tetradymia canescens – herbarium sample Sample showing typical stems: Stems highly branched, new growth silvery canescent tomentose. Simple leaves, woolly-canescent, silvery. Flowers: heads with 4 phyllaries, disk florets bright yellow.Tetradymia canescens - Autecology Plant Attributes •Warm season shrub •Relatively deep taproot •Insect pollinated (moths, bees, flies, beetles) •High seed production •Low seedling survival, slow population turnover •Regeneration by resprouting from root crown •Occurs in all successional stagesTetradymia canescens - Autecology Forage Quality, Palatability, and Cover • Poor value as livestock forage species •Toxic to sheep, with small amounts (.5% body weight) causing liver damage, capillary breakage, and head swelling •Can cause abortion and poor wool quality •Low palatability for livestock and wildlife •Low in energy and protein content •Can provide fair cover/habitat for large mammals and good cover for small mammals and birdsTetradymia canescens - Autecology Drought / Stress Tolerance •Highly drought tolerant Grazing Tolerance •Increaser with high intensity grazing Fire Tolerance •Fire resistant shrub •Rapid resprouting following fire