Species · genus Mammillaria · Cactaceae

Twin-spine Cactus

Mammillaria geminispina Haw.

Also known as: Whitey

Growth habit
succulent subshrub
Native range
Mexico Gulf, Mexico Northeast
Reference · M. geminispina

Cultivars of M. geminispina

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

No named cultivars catalogued under M. geminispina 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 clustering succulent cactus from arid regions of northeastern and Gulf Mexico, storing water in its spined, globular stems. It wants gritty, fast-draining mineral mix and plenty of bright direct light. Water deeply only when the mix has dried out completely, and let it stay dry through cooler, darker months to avoid rot.

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 14-28d)
Humidity
ai:claude-opus-4-8
Soil
ai:claude-fable-5
Care
ai:claude-fable-5
Light

Direct sun

Water

≈ every 28 days

Humidity

Low — average room

Temperature

7–32 °C

Soil mix

Gritty, fast-draining cactus mix

Propagation

Offsets separated and rooted after callusing

Fertilizing

Dilute low-nitrogen cactus feed in spring and summer

Growth rate

Slow

Flowering

Deep pink flowers ringing the crown in spring

ToxicityAuthoritative · species

Not yet documented

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.

Add images

Sources: ai:claude-opus-4-8 · ai:claude-opus-4-8 (range 14-28d) · ai:claude-fable-5

Kept true by its growers

Every fact here carries its source. Grow Twin-spine Cactus 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.

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