Echinocereus POSELGERI

Echinocereus POSELGERI - Poselger's echinocereus, Echinocereus poselgeri, Wilcoxia, Dahlia Cactus.

Echinocereus is a genus of cacti in the cactus family (Cactaceae), comprising about a hundred species. All of them grow in arid regions of North America, from the southern United States to central Mexico, on rocky slopes, in deserts, and semi-deserts.

The plants vary from globose to elongated-cylindrical, solitary or clustering. The ribs are well-defined, and the areoles are large. The spines can be long and stiff, thin and soft, or arranged like a comb along the ribs.

The flowers are large, bright, and often fragrant, opening at the apex or along the sides of the shoot and breaking out right through the skin of the stem. The fruits are fleshy, edible in several species. The seeds are rounded, small, and dark.

Poselger's echinocereus is a species from southern Texas and the Mexican state of Coahuila. For a long time it was assigned to the separate genus Wilcoxia, and at one point to the genus Peniocereus, but molecular studies showed that all wilcoxias are echinocerei, and the genus was abolished.

The plant looks completely unlike a typical echinocereus: the stems are slender, no thicker than a pencil, up to 0.9 cm (0.4 in) across and up to a meter (3.3 ft) long, with 8-10 narrow rounded ribs. The areoles are set so closely together that their pubescence merges into a continuous mass covering the shoot. In nature, the stems are weak and grow leaning on the branches of spiny shrubs, in whose shade the species settles. Underground it has a cluster of tuberous roots resembling those of a dahlia - hence the English name dahlia cactus. The flowers are broadly funnel-shaped, 2.5-5 cm (1-2 in) across, white, pink, or red, staying open for about two days and continuing to enlarge all that time.

Echinocereus seeds are small, rounded, dark, maturing in fleshy fruits. Soaking such small seeds is impractical, so the substrate itself is disinfected: before sowing, it is drenched with a weak solution of potassium permanganate and dried slightly. Scarification and stratification are not required.

Sowing is performed on the surface of a moistened mineral substrate with a pH of 6.0-6.5, without burying. The sowing is moistened from a spray bottle with a growth stimulant solution: SUPERthrive, HB-101, Aminosol, Epin, or Zircon, covered with a lid or glass or placed in a propagator, and germinated at a temperature of 24–28 °C (75–82 °F) with regular ventilation.

Under favorable conditions, the first sprouts appear within 7 days, main germination is completed in 7-15 days, while individual seeds can delay for a very long time - from 4 to 12 weeks, and sometimes for several months. For cacti this is normal, and sowings should not be discarded prematurely. Pricking out is carried out after the appearance of the first spines: young plants tolerate it well.

© Greeniverse. All rights reserved.

The plant is placed on a south or southwest window with bright sunlight. Direct rays are permissible most of the year. Good ventilation and low air humidity are required.

In summer, a temperature of 22–30 °C (72–86 °F) is maintained, in winter around 8–12 °C (46–54 °F). A cool dry wintering is mandatory: without it, the plant will not set flower buds.

Watering is carried out only after the substrate has completely dried out. In winter, watering is stopped completely to ensure a dormant period.

A mineral substrate is used, with the addition of coarse sand, perlite, and gravel. The pot must have drainage holes, and drainage is placed at the bottom.

Fertilizer is applied once every 4 weeks from spring to autumn, using a cactus fertilizer with low nitrogen content. During the winter period, feeding is not needed.

Repotting is performed in spring, once every 2-3 years. Shaping is not required. In addition to seeds, the species is easily propagated by cuttings: they form typical tuberous roots within a year. New plants can also be obtained by dividing the tubers themselves.