All the information and photos in cactus art file are now available also in the new the Enciclopedia of Cacti. We hope you find this new site informative and useful.

E. johnstonii Las Vegas, Nevada, USA
The stem of this  fascinating cactus is almost completely hidden by the interlocking grey-pink to grey-brown spines except for the apex that is more or less devoid of spines, but with a heavily felted-over circular patch 1-1,5 cm in diameter.
 

Cultivation: This is one of the most beautiful cacti but rarely seen in cultivation, it needs perfect drainage to flourish.  It is quite difficult to grow on its own roots. Very easily rot! It’s thought that’s better to watch this species in photo or in the natural habitat rather than to try to cultivate it. For this reasons the plant is often  grafted on a frost hardy stock.
This plant need full sun and above all a very good ventilation, especially in winter. Keep totally dry during winter.  It can tolerate temperature below zero (-15° C or less). Mature individuals - if the growing conditions are not optimal,  easily rot and die.

Propagation: Seeds are relatively difficult to germinate  (only a limited percentage of seeds germinate).  Grafting is often used to speed growth rate and to create a back-up for plants in collection.

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Accepted Scientific name:  Echinomastus johnsonii (Parry ex Engelm.) E.M. Baxter
In: Calif. Cactus 75. 1935.

Origin:  USA, South Utah, Nevada, California (Dead Valley area) Arizona.

Conservation status: Listed in CITES appendix 2.

Habitat:  It grows in a very arid and dry environment,  in the Mojave desert scrub and upper edge of Sonoran desert scrub on rocky hillside on gravelly hills in lime-stone impregnated soil, Altitude 500-1400 m;

Synonyms: For Joseph E. Johonson (1817-1822) US-American amateur and botanist of st. George Utah.

Common English Names include:  Johnson's fishhook cactus.

Synonyms:

• Echinocactus johnsonii Parry ex Engelm
  In S. Watson, Botany (Fortieth Parallel), Bot. King. Expl. 117. 1871 (as johnsoni).
• Echinocactus johnsonii Parry ex Engelm. var. lutescens Parish
• Echinomastus johnsonii var. lutescens (Parish) Wiggins
• Echinomastus johnsonii var. octocentrus J.M. Coulter
  In: Contr. U.S. Nat. Herb. 3: 374. 1896 Echinomastus arizonicus Hester.
• Neolloydia johnsonii (Parry ex Engelm.) L.D. Benson
• Neolloydia johnsonii (Parry ex Engelm.) L.D. Benson var. lutescens (Parish) W.T. Marsh. ex R.G. Engard
• Sclerocactus johnsonii (Parry ex Engelm.) N.P. Taylor
• Ferocactus johnsonii Britton & Rose
  In: cactaceae 3: 141. 1922
• Thelocatus johnsonii W.T.Marshall ex Kelsey & Dayton

Description: Echinomastus johnsonii is a small “barrel cacti” almost completely hidden by the interlocking spines. Usually solitary (or occasionally branching after injury to the apical bud). This plant varies geographically in both flower and spine colour.
Stems Ovoid to ellipsoid-cylindroid, 10-25 cm long, 7-15 cm in diameter. Apex more or less devoid of spines, but with a heavily felted-over circular patch 1-1,5 cm in diameter at the apex.
Ribs: (13-)18-21, narrow, undulate, strongly indented just above each tubercle and rising gradually to the next. Tubercles protruding approx 5-8 mm.
Areoles: (14-)21-26 mm apart along ribs with a short, narrow woolly groove running from the upper margin of the areole to the axil of the tubercle, areolar glands present at least seasonally.
Spines 13-24 per areole, spreading, often intricately intertangled, acicular, greysh to pale yellow, tienged in pink-reddish, lavender to maroon and often blackening in age.
Radial spines: 9-16 per areole, stouter, more or less bulbouse at the base, divaricately spreading; abaxial (shortest) radial spine 6-19 mm; adaxial and lateral (longest) radial spines ca. 27-40 mm (often lighter in colour)
Central spines: 4-9 per areole, present at all ages, spreading straight or slightly curving, never hooked, 27-41 long.
Flowers Funnel form 4-6 cm long, 4-7,5 cm in diameter; inner tepals yellow or pink to magenta with a silvery sheen, basal portions blotched with maroon . Scale of the ovary obtuse, menbranous on margins.Stigma lobes yellowish white to green.
Blooming season: Flowering (Feb-)Mar-May; fruiting Apr-Jun
Fruits: Green drying to tan, nearly naked, dehiscent only along single, longitudinal split, spheric to oblong, 10-18 mm.
Seeds: Papillate, finely reticulate-pitted, broader then long.

Note: The yellow-flowered plants have been named E. johnsonii var. lutescens. The pink-flowered plants occur in separate populations, as far as is known, to the north of the yellow-flowered plants.

All the information and photos in cactus art file are now available also in the new the Enciclopedia of Cacti. We hope you find this new site informative and useful.