Echinocereus pectinatus

A comb-spined cactus of northern drylands

Echinocereus pectinatus was first described in 1838 and moved to Echinocereus in 1848. It is native mainly to northern Mexico, with one accepted subspecies extending into southwestern Texas. Regional variation has produced several forms and names across this wide dryland range.

The species grows in desert and dry shrubland, often on stony slopes, gravelly flats or limestone ground. It experiences strong sun, moving air, sharp temperature changes and rain concentrated into short seasonal events. Cylindrical stems store water, and neat comb-like spines lie close to the surface. This compact growth suits the open country in which the species developed.

Seasonal care for a dry-growing plant

Support, propagation and repotting

A well-lit stem needs no stake. Allow basal offsets to form a natural clump, or separate a rooted offset during repotting once it releases without tearing the parent.

Watering

In active warm growth, soak the substrate completely after it has dried through, then allow unrestricted drainage. Keep almost dry during a cold winter rest.

Light

Give Echinocereus pectinatus abundant direct sun at a south- or west-facing window, increasing exposure gradually after purchase. Excess sun usually causes trouble only after an abrupt move from shade, showing as pale or corky patches.

Substrate and roots

Use a predominantly mineral cactus mix of pumice, lava, coarse grit or calcined clay with a limited organic fraction. A pot only slightly wider than the plant or clump is adequate.

Temperature

Grow actively in warm growing conditions with sun and ventilation. A completely dry plant benefits from a cool winter rest cool but frost-free conditions and may tolerate brief colder conditions, but a potted indoor specimen should be protected from hard freezing.

Fertilising

Apply a low-nitrogen cactus fertiliser at a low dose during active root and stem growth. A recently repotted plant with some organic nutrition may need only one or two light feeds.

Root, stem and leaf problems in Echinocereus pectinatus

• Spines lie flat in neat comb-like rows: This combed spine arrangement is normal and gives the species its name. It should not be scraped away as scale, mould or residue.
• The body shrinks slightly during a cool dry winter: Modest firm contraction can be normal during rest. Keep watering very cautious until active growth returns; a mushy or discoloured base is rot, not healthy winter shrinkage.
• The cactus loosens in its pot: This species has a relatively small, disturbance-sensitive root system, but sudden instability can also mean root loss. Tip the plant out carefully, check for mealybugs or decay and avoid an oversized replacement pot.
• White fluff appears at the base or among the roots: Mealybugs can attack above or below the soil line. Isolate the cactus, inspect the entire root ball and follow our mealybug guide, replacing infested mix when root pests are present.

Echinocereus pectinatus has sharp parts

• Keep this plant away from children and pets because its effects after chewing or swallowing are unclear.
• Sharp spines can puncture the mouth, eyes, skin or paws.
• Handle it carefully. Contact a veterinarian or medical professional after a serious injury, especially to the eye.

Why is it called Echinocereus pectinatus?

Echinocereus combines Greek echinos, meaning hedgehog, with Cereus, referring to its spiny stems. The Latin epithet pectinatus means combed or comb-like, referring to the arrangement of the radial spines.

Georg Engelmann established the genus Echinocereus in 1848 in Memoir of a Tour to Northern Mexico, page 91.

Michael Joseph François Scheidweiler first described it as Echinocactus pectinatus in 1838 in Bulletin de l’Académie Royale des Sciences de Bruxelles, volume 5, page 492. Georg Engelmann later placed it in Echinocereus as Echinocereus pectinatus in 1848 in Memoir of a Tour to Northern Mexico, page 110.