Green antelopehorn, Green milkweed
Asclepiadaceae (Milkweed Family)
Marcus, Joseph A.
Green antelopehorn is a native, perennial
forb or herb
with alternate, entire
leaves. The leaf margins are often wavy. Flowers are white and in an umbel,
mostly one per plant. Upon close inspection, some rose or purple color is evident in the center of each individual flower
(gynostegium). The milky substance that is exuded when a plant part is broken is very sticky, much resembling “Elmer’s glue.” These milkweeds bloom from late spring to middle summer.
This milkweed is common in pastures from Kansas to Texas. Generally avoided by cattle and horses. It can be found along roadsides, ditches, prairies, open areas, and other areas with little vegetative competition. The flowers are distinct in that they lack horns.
Image Gallery: 42 photo(s) available
Plant CharacteristicsDuration: Perennial Habit: Herb Root Type: Tap Leaf Retention: Deciduous Leaf Arrangement: Alternate Leaf Complexity: Simple Leaf Shape: Lanceolate
, Ovate Leaf Venation: Pinnate Leaf Pubescence:
Puberulent Leaf Margin: Entire Leaf Apex: Emarginate Leaf Base: Truncate Breeding System:
Flowers Bisexual Size Notes:
9 ¾ – 25 ½ in (25-65 cm). Leaf:
Leaf arrangement is alternate
to sub-opposite and attachment is petiolate with short petioles. Leaves ovate
2-4 ¾ in (5-12 cm) long and 3/8- 2 ¼ in (1-5 ½ cm) wide. Glabrous,
but occasionally has fine sparse hairs. Flower:
Usually one umbel
but large plants may have up to 10 stems and infloresences, 3-5 in (7 ¾ -12 ¾ cm) wide with 10 +/- flowers per umbel. Color is white to yellow-green with a purple tinge. Corolla
is green or cream. Hoods are purple to white. Corolla
cups upward and around the outside of the hoods. Doesn’t have horns. Fruit:
Pods usually erect, 2 ½ -5 in (6-13 cm) long and ½ – ¾ in (1-2 cm) wide. Slightly hairy. Size Class:
Bloom InformationBloom Color: White , Yellow , Green , Purple
Bloom Time: Apr , May , Jun , Jul , Aug , Sep
Bloom Notes: Flowers details are beautiful in how they are arranged in the cluster.
, WV Native Habitat:
Dry areas, prairies, pastures, glades, ditches, disturbed ground, limestone soils.
Growing ConditionsWater Use: Low
Light Requirement: Sun
Soil Moisture: Moist
Cold Tolerant: yes
Heat Tolerant: yes
Conditions Comments: This is another member of the milkweed family that certain butterflies love. It can be found growing in rich or poor soils and blooms off and on over ther growing season through the end of summer. Has a spreading, open growth form. Requires little water and full sun.
All plants in the genus
Asclepias are probably somewhat toxic, some fatally so, to both humans and animals. The sap
of some causes skin irritation in humans. Sensitivity to a toxin varies with a person’s age, weight, physical condition, and individual susceptibility. Children are most vulnerable because of their curiosity and small size. Toxicity can vary in a plant according to season, the plant’s different parts, and its stage of growth; and plants can absorb toxic substances, such as herbicides, pesticides, and pollutants from the water, air, and soil. Conspicuous Flowers:
Butterflies Nectar Source: