Echinocereus waldeisii
(Synonym: Wilcoxia waldeisii)

Photo courteously provided by Dieter & Irene Waldeis
E. waldeisii is more floriferous and also easy to cultivate on its own root than E. tamaulipensis.

Description: The peculiarity of Echinocereus waldeisii is that it forms only a single stem,  that can branch out in the age, but not in the same extent as the similar species E. tamaulipensis. The stems are clambering through the adjacent vegetation and arise from a tuberous, dahlia-like  root-stock.
Stem: Slender cylindrical, with pointed growing tips, dark blue-green to purplish o brownish 60-120 cm long about 2 cm in diameter.
Ribs: Flat, without tubercles.
Central spine: One, pointed toward the stems tip, slightly flattened, dark reddish, up to 10 mm long.
Radial spines: 8-16, thin, bristle-like, whitish or grayish, with dark tips, up to 5mm long.
Flowers: Terminal or borne near the tips of older stems, narrowly funnelform that often fail to open completely, up to 6cm long and 4 cm in diameter.
Fruit: ovoid, dark green to brown, indehisent, with persistent spines and wool.

Cultivation:  Do not over water. They need to be kept in a cool and dry place during winter rest  this is important for the flowers as well as for their health. Without this cool winter period they normally wont get any buds. It  is quite frost hardy -7 (-10)° C.

Sun Exposure: Best in full or partial sun exposure.

Scientific name:  Echinocereus waldeisii E. Haugg 1994

Holotype: Mexico: San Luis Potosi, East Huizache crossing, Depositated by D.WALDEIS 1988 [WU]

Section: Wilcoxia

Synonyms: 

• Echinocereus tamaulipensis ssp. waldeisii (E. Haugg) M. Lange. Kakt. and. Sukk. 46(6): 140, 1995
• Echinocereus tamaulipensis ssp. deherdtii M. Lange. Kakt. and. Sukk. 46(6): 142, 1995
• Echinocereus poselgeri waldeisii

Common Names include: Sacasil, Zocoxochitl, Dahlia Cactus, Pencil Cactus & Lead Pencil Cactus.

Distribution: Mexico: San Luis Potosi, from south of Matehuala to Villa ldalgo and from east of Huizache crossing to the junction for Tula at an elevation of 1200 1500 above sea level.

TAXONOMY: The Reason of the rehabilitation  into the species status of E. waleisii is that E. waldeisii - in contrast to E. tamaulipensis - form a storage organ in each root branch developing from the central stalk reminding the dahlia tubers. Each plant has up to 8 slender tubers that measure 20 30 mm in diameter and 80-100 mm long. In the youth they are pale-brown and later became black-brown.

Photo of conspecific taxa, varieties, forms and cultivars of plants belonging to the Echinocereus posselgeri (Wilcoxia) complex (This Taxon has lots of synonyms ( like many other cacti) whit several controversial varieties and subspecies and comprises different forms):

• Echinocereus kroenleinii
• Echinocereus leucanthus
• Echinocereus posselgeri
• Echinocereus waldeisii (E. tamaulipensis ssp. waldeisii)