Similar to, but taller and more impressive than, E. tescorum, this species occurs in the hilly region south of Lake Turkana in Kenya on rocky slopes with open bushland between 900 and 1800 m.
The plants grow into sturdy shrubs up to 2.5 m tall, with many 2-3 cm wide branches. These have 4-5, sometimes 6, angles; uniformly green or sometimes with somewhat darker blotches around the spine-shields; slightly constricted every 10-20 cm. The strong spines are to 1 cm long.
The name (with dark flowers) refers to the crimson cyathia; the fruits are almost black.
The pictures were taken about halfway between Baragoi and South Horr on 23 Sept 2015. Altitude about 1440m.
The first picture shows a healthy stand of Euph. magnicapsula ssp. lacertosa in the background.