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Summit County Weed Department 1755 South Hoytsville Road [PHONE REDACTED] [EMAIL REDACTED] www.summitcounty.org/weeds Poisonous Weeds A guide to weeds that are Poisonous to Horses and other livestock in Summit County, Utah. Houndstongue Poison Hemlock Yellow Starthistle Death Camas ---PAGE BREAK--- i Introduction Poisonous plants in Summit County can be found in almost all plant communities throughout the county. Like most livestock they will leave poisonous plants alone because of discriminating tastes. However, horses when confined to stalls and fed dry hay or restricted to marginal pastures, may sample large numbers of green plants and accidentally or intentionally ingest poisonous plants in their system when allowed to graze. In most cases, animals only consume poisonous plants when their pasture has been over grazed. Another problem is lawn clipping especially for horses. A surprising number of ornamental trees and shrubs used for landscaping are toxic to horses. Prevention Suggestions: It is important for horse owners to survey their property very carefully and check for any toxic plants. Persistent efforts to eliminate or control poisonous plants in your home pastures are essential. If there are only a few plants they can be dug up and disposed of before they spread to larger areas. If the infested area is too large, troublesome plants can be sprayed with the appropriate herbicide. One of the best ways to keep weeds out is to work towards a healthy stand of legumes and grasses, cut weeds down before they seed, do not over graze your pastures. Try to keep hay during winter feeding as weed free as possibly. Preserving and protecting lands not presently infested, is the first line of defence against aggressive noxious weeds. Prevention requires awareness and action by the land owner as well as the general public, to recognize, report, and control new infestations before they have a chance to expand and spread. 20 Published by the Summit County Weed Department Contact Information Summit County Weed Department [PHONE REDACTED], [PHONE REDACTED] or [PHONE REDACTED] ext. 3979 USU Extension Office, Summit County [PHONE REDACTED], [PHONE REDACTED] or [PHONE REDACTED] ext. 3217 Weed control equipment is available for public use, by appointment only. Equipment available includes: Back Pack Sprayers, ATV Sprayer, Truck Sprayer, and a Tractor Sprayer. Equipment may be borrowed, at no cost, for up to two weeks. The Summit County Weed Department also sales select weed control chemicals. Call for more details. This book is printed by Summit County Utah © 2012 Summit County Utah ---PAGE BREAK--- 19 ii Table of Contents ARROW GRASS 1 DEATH CAMAS 2 LOW LARKSPUR 3 DUNCECAP LARKSPUR [TALL LARKSPUR] 4 WYETH’S LUPINE 5 WATER HEMLOCK 6 POISON HEMLOCK 7 BLACK HENBANE 8 HOUNDSTONGUE 9 FIELD HORSETAIL 10 SILVER 11 SCRUB OAK 12 WESTERN WHORLED MILK WEED 13 LOCO WEED 14 CHOKE CHERRY 15 BITTER NIGHT SHADE 16 YELLOW STARTHISTLE 17 SMOOTH SCOURINGRUSH 18 Contact Information Summit County Weed Department [PHONE REDACTED], [PHONE REDACTED] or [PHONE REDACTED] ext. 3979 USU Extension Office, Summit County [PHONE REDACTED], [PHONE REDACTED] or [PHONE REDACTED] ext. 3217 ---PAGE BREAK--- 1 ARROWGRASS (Delphinium Occidentale) Description: Arrowgrass has fleshy, dark green, half round leaves that grow from the base of the plant. Although clumps of leaves are only 6 to 8 inches tall, slender flower stalks reach a height of 3 to 5 feet. Small green flowers appear close together, up along the upper part of stem. The flowers develop into golden brown fruits. This plant is a perennial. Arrowgrass grows best in wet condition. How it affects livestock: As long as Arrowgrass has plenty of moisture it does not cause poisoning. After frost and or ground has dried up it quickly becomes toxic. It takes about 1/4 to 3 pounds to kill a 600 lb cow depending on how stunted the Arrowgrass is at the time it is consumed. The toxic dose must be eaten at one time to cause death. What to look for: 1– Nervousness 2– Abnormal breathing, either very rapid or slow and deep 3– Trembling or jerking muscles 4– Blue color of mouth lining 5– Spasms or convulsions Contact your local vet, there is some help if immediate treated Treatment: 0.5 ounce per acre of Escort in spring or early summer. 18 MEADOW DEATH CAMAS (Zigadenus venenosus) Description: Meadow Death Camas is an erect perennial with stems 8 to 18 inches tall and has oval bulbs covered with blackish scales. Its leaves are basal, grass like 6 to 8 inches long 1/2 to 3/4 inches broad. Death Camas has many flowers in a simple, terminal, spike like cluster. The flowers are yellowish–white and sometimes it has all yellow blossoms. The seeds of Death Camas are light brown capsules. Death camas is one of the first plants to start growing in the spring, unless there is sufficient other forage, death camas will be grazed and will cause severe losses. How it affects livestock: Sheep are most likely to be affected by feeding on death camas, cattle and horses can be affected. Plants are dangerous at all times of the year, leaves, stems, flowers, all parts are toxic. What to look for: 1– Rapid breathing 2– Excessive salivation and nausea 3– Weakness and staggering 4– Convulsions and coma Treatment: Spray early spring when plant is actively growing. 1.5 ounces of Weedmaster per gallon of water. Or Escort at 1 oz. per acre. ---PAGE BREAK--- 17 LOW LARKSPUR - Crow foot family (Delphinium bicolor) Description: Low larkspur is found on grassy hill sides, in sage brush areas, and in dryer pastures. Larkspur is a perennial with a spurred blue flower that grows on the top third of a single stem. This plant is 4 to 8 inches tall, but can reach up to 2 feet tall. Leaves are alternate and are divided into deep narrow lobes. The stem is hollow. Larkspur begins growing in early spring, often before other forage, making it the first green feed available. Low larkspur grows from 4,000 to 10,000 foot altitudes. How it affects livestock: Larkspur causes more cattle losses than sheep or horses. Cattle like to feed on larkspur where sheep and horses prefer other plants. What to look for: 1– Nervousness 2– Staggering 3– Nausea and excessive salivation 4– Twitching muscles 5– Bloating 6– Irregular heart action and respiratory paralysis Contact your local vet, there is some help if immediate treated Treatment: Escort at 1.5 ounces per acre in spring in rosette stage 2 DUNCECAP (TALL) LARKSPUR (Delphinium occidentale) Description: Tall Larkspur is a perennial in the crowfoot family that is found in thick clusters on hillsides and in meadows. It usually grows at altitudes of 8,000 to 11,000 feet. Tall Larkspur can grow up to 5 feet tall and has a spurred blue flower. The leaves are broad and divided into deep lobes. Tall larkspur reaches a poisonous peak during early summer and then decreases after flowering but is still dangerous. How it affects livestock: All parts of tall larkspur is toxic, Larkspur is highly palatable to cattle, especially after the plant has flowered. Cattle frequently die within 3 to 4 hours of consuming a lethal dose of 20 to 25 lbs for a large animal. Horses and sheep usually do not eat this plant but it can kill them also. What to look for: 1– Staggering 2– Falling 3– Bloating 4– Convulsions and 5– Muscle Quivers Treatment: Escort at 1.5 ounces per acre in spring in rosette stage ---PAGE BREAK--- 3 WYETH’S LUPINE (Lupinus Wyethiis) Description: Lupine is a perennial that grows on foothills, mountain ranges, in sage brush and aspen areas. Lupine has an extensive root system and has stems that grow up to 18 to 20 inches tall. Lupine’s flowers are mostly blue but can be white, or pink to purple. Poisonous species of lupine are dangerous from the time they start growth in early spring until they dry up in the fall. The most dangerous time is the seed stage. How it affects livestock: For sheep it only takes 1/8 to 1/4 pound of lupine daily for 3 or 4 days. Cattle are poisoned by eating 1 to 1.5 pounds for 3 to 7 days. It can affect their calves if a cow feeds on lupine between 40th and 70th days after breeding. Even though some lupine is not toxic, precautions should always be taken with livestock. What to look for: 1– Rough, dry coat 2– Nervousness 3– Depression 4– Difficulty in breathing 5– Twitching Muscles 6– Frothing of the mouth 7– Convulsions Treatment: 2 quarts of 2, 4-d per acre at growing stage to bud stage. Weedmaster will work at 1.5 oz. per gallon of water. 16 WATER HEMLOCK (Cicuta Maculatum) Description: Water hemlock is a perennial that grows in wet seepage areas of meadows, pastures, and along ditch banks. Hemlock can reach heights of 2 to 3 feet. Water hemlock has small, white flowers that grow in umbrella like clusters. The leaves are long and narrow and toothed or notched. How it affects livestock: Water hemlock is probably the most poisonous plant that grows in the United States only a small amount of the toxic substance is needed to produce poisoning in livestock— or in humans. Livestock usually show signs of poisoning 1 to 6 hrs after they eat the plant and die within 2 hours after signs appear. What to look for: 1– Twitching Muscles 2– Rapid Pulse 3– Rapid Breathing 4– Tremors 5– Convulsions 6– Frothing of the mouth 7– Coma Treatment: 2 quarts per acre of Weedmaster or 1.5 oz. of Weedmaster per gallon of water. Apply at flower bud stage. ---PAGE BREAK--- 15 POISON HEMLOCK (Conium Maculatum) Description: Poison hemlock is a native of Europe, now distributed across the United States found along roadsides, fence lines, ditches, and waste areas. Poison hemlock can grow to be about 6 to 10 feet tall and characteristically has light red spots on the stem. The flowers are white in color and are borne in many umbrella– shaped clusters that support a stock, flowers being white in color. Foliage has a strong musty odor. How it affects livestock: Poison hemlock is a range plant that kills many animals in the western United States. Sheep, cattle, horses and extremely poisonous to man. All parts are poisonous. What to look for: 1– Nervous trembling 2– Bloating 3– Blue coloration around mouth 4– Respiratory Paralysis 5– Coma Treatment: 1 to 2 quarts per acre of Weedmaster or 1.5 oz. of Weedmaster per gallon of water. Apply at early bud stage. 4 BLACK HENBANE (Hyoscyamus Niger) Description: Black henbane is a native of Europe, commonly found in waste places, pastures, right of ways and fence lines. Black henbane is a biennial or sometimes an annual. The leaves have pointed lobes and prominent veins. Black Henbane has white flowers with purple centers and veins are I to 2 inches wide bearing pineapple shaped fruit in leaf axils. Each fruit has 5 lobes and contains hundreds of tiny black seeds. The entire plant is covered with greasy hairs and the entire plant has a foul odor. How it affects livestock: This plant is toxic to both animals and humans. Sometimes it is used in the medical field in controlled substances. Treatment: Treat from rosette to bolting stage. 0.5 to 1.0 ounce per acre of Escort or Tordon at 1.5 pints per acre. ---PAGE BREAK--- 5 HOUNDSTONGUE (Cynoglossum Officinate Description: Houndstongue is a biennial that is native to Eurasia that is found along roadsides, trails, pastures, woodlands and disturbed areas. Houndstongue grows from 1 to 4 feet tall and has leaves that are basal about 3 inches wide with a hairy surface, upper leaves are narrower about 1 inch wide and have curled appearance and clasp the stem. The flowers are small and cluster at upper portion of the plant along stems borne in leaf axils. Each flower produces 4 green, bur-like fruits that turn brown as they mature. How it affects livestock: Houndstongue contains alkaloids that are especially toxic to cattle and horses. The plant is rarely eaten in the green state; however, animals will eat the dried plant in hay where they are more likely to ingest toxic levels. Fatal liver disease has occurred after 2 weeks of feeding hay with as little as 6% Houndstongue. Treatment: Treatment Weedmaster at 2 quarts per acre or Escort at 1 ounce per acre. 14 FIELD HORSETAIL (Equisetaceae) Description: Horsetail is a perennial that is most often found in wet to moist areas but once it is established will grow well in moderately dry areas. Field Horsetail has aerial stems and underground tuber-bearing root stocks. A fertile cone-bearing stem which arises in early spring is flesh– colored and .5 to 1 foot tall with cones .75 to 1.5 inches long. A vegetative stem arises after the fertile stem and is 1.5 to 2 feet tall with many whorls of green jointed branches. How it affects livestock: Horsetail is poisonous to animals, particularly horses, when eaten in large quantities of hay containing 20% or more horsetail. What to look for: 1– Weakness in hind quarters 2– Lack of coordination 3– Appetite remains normal until just before death Treatment: Treat with Telar at 1.5 ounces per acre before spore heads are formed. ---PAGE BREAK--- 13 SILVERLEAF (Solanum elaeagnifolium) Description: Silverleaf is native to America and has a deep rooted branched perennial herb. It can be found in grain fields, vegetable crops, roadsides, pastures and railroads. Silverleaf is 1 to3 feet tall with stems sparsely covered with short yellow thorns. The leaves and stems are covered with dense short hairs that give the foliage a grey or silvery appearance. Leaves are narrow, lance-shaped with wavy margins. Flowers are .75 to 1 inch wide and are violet to light blue in color. Fruit holds the seeds and is green turning to orange when ripe. How it affects livestock: This species is toxic to livestock and cattle that consume 0.1% to 0.3% of their body weight in ripe berries display moderate poisoning What to look for: 1– Rapid breathing 2– Salivation and slobbering 3– Nasal discharge 4– Weakness 5– Lack of coordination Treatment: Banvel at 2 to 4 ounces per acre or Weedmaster at 1.5 ounces per gallon of water depending on the crop it is mixed with. 6 SCRUB OAK (Quercus Dumosa) Description: Scrub oak, also called Gambel oak, is a woody perennial found throughout the central part of the western states. Scrub Oak is found on foothills and mountain slopes between 6,000 and 9,000 feet elevation and may be 3 or 4 feet high or as high as 20 feet depending on the soil. Oak leaves are leathery and deeply lobed and the acorns form at base of stem. How it affects livestock: Poisoning is caused by young browse, sprouts in cutover areas, mature foliage on felled trees, acorns, and fallen leaves. Oak is most dangerous in budding and leafing stages. As the leaves mature Scrub oak decreases in toxicity. Cattle may get as much as 50% percent of their diet from oak without showing signs of poisoning. More than 50% will cause sickness, more than 75% of their diet it will cause death. What to look for: 1– Gaunt 2– Diarrhea 3– Weakness 4– Dark colored urine 5– White mucus in droppings Treatment: 1 to 2 ounces of Escort per acre when leaves are young. ---PAGE BREAK--- 7 WESTERN WHORLED MILK WEED (Asclepias Subverticilate) Description: Milk Weed is native to the western United States and typically grows on old farms that are abandoned, ranges, pastures and roadsides. Milk weed is a perennial that reproduces by seed and deep rooted horizontal roots. Stems are slender 1 to3 feet tall, smooth, erect, and un-branched, arising from a branched root crown either singly or in clumps. The leaves are narrow and up to 3/8 inch wide and 2 to 5 inches long. The flowers are found in umbrella like cluster and are green–white. How it affects livestock: Milk Weed is toxic at all times and is most dangerous during growing season. Milk Weed poisoning occurs frequently in sheep and cattle, and occasionally in horses. What to look for: 1– Bloating 2– Respiratory problems 3– Violent spasms 4– Rapid and week pulse 5– Loss if muscular control Treatment: Tordon or Banvel at 2 quarts per acre in bud stage to early bloom. 12 LOCO WEED (Disambiguation) Description: Loco Weed is a biennial which grows on foot hills, plains, and semiarid regions. Loco Weed grows close to the ground, about 4 to 8 inches tall, and the flowers resemble sweet peas with blossoms that are blue, purple, yellow, or white. There are several different species of Loco Weed with some of the more toxic being white, purple, blue, big bend, and western loco weed. How it affects livestock: Loco Weed is poisonous in all stages of growth and is dangerous at any time of the year. Animals ordinarily do not feed on Loco Weed unless feed is scarce and after eating it they may prefer Loco Weed to good forage. An animal must eat large amounts of locoweed for 2 to 5 weeks before death occurs. Signs of poisoning appear after 2 to 3 weeks of continuous grazing on the plant. What to look for: 1– Loss of flesh 2– Irregular gait 3– Loss of direction 4– Nervousness 5– Weakness 5– Violent Actions Treatment: Weedmaster 1.5 to 2 ounces per gallon of water or Escort 1 ounce per acre. Treat when plants are actively growing. ---PAGE BREAK--- 11 WESTERN CHOKECHERRY (Prunus Virginiana Demissa) Description: Western chokecherry is a perennial that is native to the United States and grows where moisture is plentiful. It is found in thickets on hillsides and canyon slopes. Chokecherry is in the rose family and appears as a shrub or small tree around 20 feet tall. It prefers moist areas, ditch banks, springs, etc. Chokecherry bears masses of white flowers in long clusters in the spring. The leaves are dark green and glossy. How it affects livestock: There is usually enough hydrocyanic acid in 2 to 4 ounces of green chokecherry leaves to kill a 100 pound sheep. 1.5 pounds of chokecherry leaves will kill a 500 lbs. cow. Wilted leaves, as well as fresh leaves, are poisonous. For chokecherry to be fatal, an animal must eat a toxic dose in a short period of time. What to look for: 1– Nervousness 2– Abnormal Breathing 3– Jerking muscles 4– Respiratory failure Treatment: Cut or spray with 2,4-D when are young and growing. 8 BITTER NIGHT SHADE (Solanum Dulcamara) Description: Bitter Night Shade is a native to Europe and Asia that lives in a wide range of habitats, from woodlands to scrublands, hedges and marshes. It is very invasive and is widely spread by birds. Bitter Night Shade is a semi–woody perennial climbing vine that scrambles over other plants. It is very invasive and is capable of reaching a height of 4 meters where support is available. The leaves are 4-12 cm long, roughly arrowhead- shaped and often lobed at the base. The flowers are in loose cluster of 3 to 20 star–shaped, with 5 purple petals with yellow stamens and style pointing forward. The fruit is an ovoid green berry about 1 centimeter long that turns red when ripe. The fruit is soft and juicy. How it affects humans: Although fatal, human poisoning is rare and several fatal cases have been documented. It is most poisonous to small children because of their body size. Treatment: Weedmaster at 2 ounces per gallon of water Or Escort at 1.5 ounces per acre. Apply when plant is young and actively growing. ---PAGE BREAK--- 9 YELLOW STARTHISTLE (Centaurea Solstitialis L) Description: Yellow Starthistle is native to the Mediterranean Basin region and grows well on dry hill sides, roadsides, and waste areas. Yellow Starthistle is a winter annual which grows from 2 to 3 feet tall. This plant is blue-green in color with rosette leaves that are deeply lobed and could be mistaken for dandelion’s rosette. The stem are sparsely leaved and heavily ridged. Starthistle’s flowers are yellow with cream colored thorns that are .25 to .75 inches long and protrude from the flowering heads. It blooms in early spring. How it affects livestock: Yellow Starthistle is a plant toxic to horses, causing chewing disease. Treatment: Milestone at 5 to 7 ounces per acre or Tordon at 2 quarts per acre. Apply when plant is in rosette form and is actively growing. 10 SMOOTH SCOURING RUSH (Equisetum Laevigatrum) Description: Smooth Scouring rush is a perennial which can be found either along stream banks, or in relatively dry soils. Smooth scouring rush has a deep spreading root stock. The stems are rough, jointed ,and hollow. The leaves are scale– like appendages located at stem nodes. Scouring rush is coarse with evergreen stems and very apparent bands at the base of each collar. How it affects livestock: Scouring rush can be toxic to young horses, sheep, and cattle especially when hay has been cut and dried in any large amounts. Treatment: 1 to 3 ounce per acre of Telar. This plant is very hard to kill.