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Texas Toxic Plant Identification Cards

**Most dangerous plants requiring immediate action**

RanchSafety Team January 20, 2026 5 min read

What's in This Card Set

This downloadable card set gives you quick field identification for the most dangerous toxic plants found on Texas ranches. Each card includes photographs, key identification features, toxicity information, and emergency response guidance. Print these cards and laminate them for use during pasture walks, new land assessments, and emergency situations.

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Card Set Contents

Set 1: High-Priority Toxic Plants (10 cards)

  • Oak (Quercus species) - buds, leaves, acorns
  • Oleander (Nerium oleander)
  • Jimsonweed (Datura stramonium)
  • Nightshade species (Solanum spp.)
  • Perilla mint (Perilla frutescens)
  • Cocklebur (Xanthium strumarium)
  • Pigweed/Amaranth (Amaranthus species)
  • Sorghum/Sudan grass (Sorghum species)
  • Water hemlock (Cicuta maculata)

Set 2: Common Texas Toxic Plants (10 cards)

  • Lantana (Lantana camara)
  • Chinaberry (Melia azedarach)
  • Johnson grass (Sorghum halepense)
  • Yellow jessamine (Gelsemium sempervirens)
  • Rayless goldenrod (Isocoma pluriflora)
  • Broom snakeweed (Gutierrezia sarothrae)
  • White snakeroot (Ageratina altissima)
  • Bladderpod (Lesquerella species)
  • Milkweed (Asclepias species)
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Sample Card Format

FRONT OF CARD

``` ┌─────────────────────────────────────────────────┐ │ [PLANT PHOTO AREA - Multiple views] │ │ │ │ ┌─────────┐ ┌─────────┐ ┌─────────┐ │ │ │ Whole │ │ Leaves │ │ Flowers │ │ │ │ Plant │ │ Detail │ │ /Seeds │ │ │ └─────────┘ └─────────┘ └─────────┘ │ │ │ │ ═══════════════════════════════════════════ │ │ LOCOWEED │ │ Astragalus & Oxytropis species │ │ ═══════════════════════════════════════════ │ │ │ │ TOXICITY: ████████░░ HIGH │ │ │ │ DANGER SEASON: March - June (peak growth) │ │ │ │ REGIONS: West TX, Trans-Pecos, Panhandle │ └─────────────────────────────────────────────────┘ ```

BACK OF CARD

``` ┌─────────────────────────────────────────────────┐ │ IDENTIFICATION FEATURES │ │ ─────────────────────── │ │ • Height: 6-24 inches │ │ • Leaves: Compound, 9-25 leaflets │ │ • Flowers: Purple, pink, or white spikes │ │ • Pods: Inflated, papery │ │ • Look-alike: Milk vetch (less toxic) │ │ │ │ TOXICITY │ │ ───────── │ │ Toxic part: All parts, especially seeds │ │ Toxin: Swainsonine (alkaloid) │ │ Lethal dose: Cumulative - 30+ days grazing │ │ │ │ SYMPTOMS IN CATTLE │ │ ────────────────── │ │ • Weight loss, weakness │ │ • Staggering, incoordination ("loco") │ │ • Depression, isolation from herd │ │ • Reproductive failure │ │ • Permanent neurological damage │ │ │ │ EMERGENCY RESPONSE │ │ ────────────────── │ │ 1. Remove from infested pasture immediately │ │ 2. No specific treatment available │ │ 3. Recovery requires 30+ days off locoweed │ │ 4. Severe cases may never fully recover │ │ 5. Call vet: _______________ │ │ │ │ AnimalSafeRanch.com | Scan for more info → │ └─────────────────────────────────────────────────┘ ```

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Individual Card Details

Card 1: LOCOWEED

  • Compound leaves with multiple leaflets
  • Flowers in spike-like clusters (purple, pink, white)
  • Inflated, papery seed pods
  • Staggering, incoordination
  • Depression, dull appearance
  • Isolation from herd
  • Reproductive failure
  • Permanent neurological damage possible
  • Provide good nutrition
  • Long recovery period required
  • Severely affected animals may not recover
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Card 2: OAK (Buds, Leaves, Acorns)

  • Lobed or wavy-margined leaves
  • Acorns with distinctive cap
  • Young growth most toxic
  • Constipation then bloody diarrhea
  • Frequent urination
  • Edema (fluid swelling)
  • Kidney failure
  • Provide calcium supplementation
  • Supportive care
  • IV fluids may be needed
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Card 3: OLEANDER

  • Narrow, leathery dark green leaves
  • Showy flowers (pink, white, red)
  • All parts extremely toxic
  • Irregular heartbeat
  • Drooling, nausea
  • Abdominal pain
  • Tremors, collapse
  • Activated charcoal if recent ingestion
  • Cardiac monitoring essential
  • Specific antidotes available
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Card 4: JIMSONWEED

  • Large, coarsely toothed leaves
  • White or purple trumpet flowers
  • Spiny seed capsules ("thorn apple")
  • Strong unpleasant odor
  • Rapid heart rate
  • Dry mouth and skin
  • Restlessness, disorientation
  • Muscle twitching
  • Difficulty breathing
  • Keep animal calm
  • Physostigmine may help (vet administered)
  • Supportive care
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Card 5: NIGHTSHADE SPECIES

  • Star-shaped flowers (white, purple, yellow)
  • Berry fruits (green, yellow, black when ripe)
  • Some with spiny stems
  • Bloating, colic
  • Diarrhea (may be bloody)
  • Weakness, trembling
  • Paralysis in severe cases
  • Supportive care
  • Activated charcoal if recent
  • Monitor for nervous signs
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Card 6: PERILLA MINT

  • Square stems (mint family)
  • Opposite, serrated leaves
  • Purple or green foliage
  • Small white/purple flower spikes
  • Strong mint-like odor
  • Open-mouth breathing
  • Extended head and neck
  • Foamy nasal discharge
  • Death within 1-4 days
  • Remove from pasture immediately
  • Keep animal calm - stress worsens
  • Supportive oxygen if available
  • Prognosis often poor
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Card 7: COCKLEBUR

  • Large, rough-textured leaves
  • Inconspicuous flowers
  • Distinctive spiny burs
  • Seedlings have thick stems, two rounded seed leaves
  • Incoordination
  • Muscle spasms
  • Convulsions
  • Rapid progression to death
  • No effective treatment once signs appear
  • Supportive care only
  • Prevention is critical
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Card 8: PIGWEED/AMARANTH

  • Alternate, oval to lance-shaped leaves
  • Dense, bristly flower spikes
  • Reddish stems/roots
  • Very common weed
  • Staggering
  • Knuckling at fetlocks
  • Recumbency
  • Breathing difficulty
  • Death (can be rapid)
  • If nitrate suspected - methylene blue (vet)
  • IV fluids
  • Often fatal if signs severe
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Card 9: SORGHUM/SUDAN GRASS

  • Broad leaves with prominent midrib
  • Large seed heads
  • Includes forages and grain crops
  • Regrowth after cutting/grazing
  • Frost-damaged plants
  • Drought-stressed plants
  • Difficulty breathing
  • Staggering
  • Convulsions
  • Bright red blood
  • Sudden death
  • Remove from pasture
  • Sodium thiosulfate/sodium nitrite (vet)
  • Often too rapid for treatment
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Card 10: WATER HEMLOCK

  • Found near water (wet areas, streams)
  • Hollow, purple-streaked stems
  • Compound leaves with serrated leaflets
  • White umbrella-shaped flower clusters
  • Chambered root base (diagnostic)
  • Excessive salivation
  • Violent convulsions
  • Rigid muscles
  • Death from respiratory failure
  • Often fatal before treatment possible
  • Anti-seizure medication if available
  • Keep airway clear
  • Call vet - rarely survivable
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How to Use These Cards

During Pasture Walks

  • Carry card set in protective case
  • Compare suspicious plants to card images
  • Note locations of any identified toxic plants
  • Mark areas on pasture map
  • Plan removal or exclusion

For New Land Assessment

  • Walk entire property systematically
  • Use cards to identify toxic species present
  • Document with photographs
  • Prioritize hazards by risk level
  • Develop management plan

For Employee Training

  • Review cards with all ranch personnel
  • Test identification skills
  • Discuss response procedures
  • Post emergency contacts
  • Schedule regular refresher training

In Emergency Situations

  • Quickly identify suspected plant
  • Follow emergency response on card back
  • Contact veterinarian with plant identification
  • Save plant sample for verification
  • Document incident
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Printing Instructions

  • Color printing essential for identification
  • Double-sided (front/back as shown)
  • Laminate for field durability
  • Plastic card holder/wallet
  • Spiral binding
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Additional Resources

Photo Reference Sites

  • Texas A&M AgriLife Extension toxic plant images
  • USDA Plants Database
  • Cornell Poisonous Plants Database
  • iNaturalist for geographic verification

Mobile Apps

  • PlantNet (plant identification)
  • iNaturalist (with Texas focus)
  • Seek by iNaturalist

Professional Identification

  • County Extension Agent
  • Texas A&M Veterinary Diagnostic Lab
  • Local veterinarian
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