Species · genus Euphorbia · Euphorbiaceae

Cow's Horn Euphorbia

Euphorbia grandicornis Blanc

Also known as: Cow Horn Euphorbia · Big Horned Euphorbia

Growth habit

succulent shrub

Native range

Eswatini, KwaZulu-Natal, Mozambique, Northern Provinces

Reference · E. grandicornis

Cultivars of E. grandicornis

The named forms growers keep — each with its own page, each honest about how much we know.

No named cultivars catalogued under E. grandicornis yet. When growers document a stable, named form, it earns its own page here.

Guide

The species-level account. Cultivar pages build on this and say where they differ.

A spiny succulent shrub from the hot, seasonally dry regions of southern Africa, storing water in its ridged green stems. Give it gritty, fast-draining mix and the brightest spot you have, ideally some direct sun. Water deeply only once the soil has dried out completely to the bottom of the pot, and err toward leaving it dry rather than wet.

Care recipe

The species record — the baseline every cultivar inherits unless it says otherwise.

Care notes are early — not yet verified

Light: ai:claude-opus-4-8
Water: ai:claude-opus-4-8 (range 14-30d)
Humidity: ai:claude-opus-4-8
Soil: ai:claude-fable-5
Care: ai:claude-fable-5

Light

Direct sun

Water

≈ every 30 days

Humidity

Low — average room

Temperature

13–32 °C

Soil mix

Very gritty mineral cactus and succulent mix

Propagation

Stem cuttings, dried to callus firmly first

Fertilizing

Sparse cactus feed once or twice in summer

Growth rate

Slow

Flowering

Rarely flowers indoors; grown for sculptural spined stems

ToxicityAuthoritative · species

Toxic to cats & dogs & humans

Euphorbiaceae produce an irritant milky latex that can harm skin, eyes, and mucous membranes. This is where toxicity lives: every cultivar of this species inherits it and none can override it.

Reference images

Every image credited. Licenses link to their deeds.

No reference gallery yet

A few clear photos — habit, a mature leaf, a flower if it blooms — would give this page its eyes.

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Sources: ai:claude-opus-4-8 · ai:claude-opus-4-8 (range 14-30d) · ai:claude-fable-5 · ai:claude-opus-4-8 (family inference)

Kept true by its growers

Every fact here carries its source. Grow Cow's Horn Euphorbia yourself? What you’ve observed — how it drinks, how it holds its color, a name that’s off — is exactly what keeps this page honest. Contributions are reviewed before anything changes.