Twin-Spined Cactus, Whitey
Mammillaria geminispina

Family: Cactaceae (kak-TAY-see-ee) (Info)
Genus: Mammillaria (mam-mil-AR-ee-uh) (Info)
Species: geminispina (jem-in-ih-SPIN-uh) (Info)
Synonym:Mammillaria geminispina subsp. geminispina
Synonym:Mammillaria albata
Synonym:Mammillaria elegans
Synonym:Neomammillaria geminispina
Synonym:Neomammillaria elegans
View this plant in a garden

Category:

Cactus and Succulents

Height:

6-12 in. (15-30 cm)

Spacing:

3-6 in. (7-15 cm)

6-9 in. (15-22 cm)

Hardiness:

USDA Zone 9b: to -3.8 C (25 F)

USDA Zone 10a: to -1.1 C (30 F)

USDA Zone 10b: to 1.7 C (35 F)

USDA Zone 11: above 4.5 C (40 F)

Sun Exposure:

Full Sun

Sun to Partial Shade

Light Shade

Danger:

Plant has spines or sharp edges; use extreme caution when handling

Bloom Color:

Magenta (Pink-Purple)

Bloom Time:

Late Spring/Early Summer

Mid Summer

Foliage:

Succulent

Other details:

Drought-tolerant; suitable for xeriscaping

Average Water Needs; Water regularly; do not overwater

Suitable for growing in containers

Soil pH requirements:

6.6 to 7.5 (neutral)

Patent Information:

Non-patented

Propagation Methods:

By dividing rhizomes, tubers, corms or bulbs (including offsets)

From woody stem cuttings

Allow cut surface to callous over before planting

From seed; direct sow after last frost

Seed Collecting:

Allow pods to dry on plant; break open to collect seeds

Allow unblemished fruit to ripen; clean and dry seeds

Properly cleaned, seed can be successfully stored

Regional

This plant has been said to grow in the following regions:

Mesa, Arizona

Phoenix, Arizona

Scottsdale, Arizona

Santa Barbara, California

Henderson, Nevada

Gardeners' Notes:

2
positives
2
neutrals
0
negatives
RatingContent
Positive

On Jul 7, 2006, palmbob from Acton, CA (Zone 8b) wrote:

THis is an easy to grow species, and a highly variable one... some have very short spines, and you can almost pick them up without endangering your fingers, while others have long, lethal spines that protrude far out from the rest, up to 2" long. Some cluster aggresively, and other seem to stay more solitary. All have pinkish flowers, some in a ring, some more randomly over the body. Maybe subspecies differences?

Neutral

On Mar 8, 2005, Xenomorf from Valley of the Sun, AZ (Zone 9b) wrote:

The differences between the varieties and Type species are:
* var. geminispina has 2 central spines that are white with darker tips.
* var. brevispina has shorter dark tipped white central spines.
* subsp. leucocentra has 5-6 pure white central spines (no dark tips).
* var. nivea is a form with pure white spines.
* var. nobilis has very long spines.

More synonyms of this plant are: Cactus elegans, Cactus geminispinus, Neomammillaria elegans, Neomammillaria geminispina, Neomammillaria neo-elegans

Neutral

On Feb 16, 2004, albleroy from Wavre/ greenhous +/- 2500 species, IA wrote:

Sorry, but the remark must be flowers in a ring in the new growth of the previous year
Greetings,
Albert (albleroy@tiscali.be)

Positive

On Nov 25, 2003, azrobin from Scottsdale, AZ (Zone 9b) wrote:

I finally found the garden spike for this one: "Flowers spring-summer in a ring after the plants new growth. Filtered/direct sun." This Mammillaria gets only better looking with age. It will continue to put on more and more heads, as well as more white cotton topping. The flowers are small and a dark pink, which encircle the top of the heads.