Xerophyte

Central Spines

1 (But often absent) stouter up to 3 cm long.

Description

Denmoza rhodacanthaSN|7993]]SN|7993]] is a large slowly growing columnar cactus. It stay globulous during a long period before becoming shortly column-shaped, 0.5 to 1.5(-2) cm high.

Flowers

They need to reach a reasonable size in cultivation before producing their flowers. First flowers appear near the top of the stem, however, on plants of very unequal age and size, some time on relatively young plants but also on 30-40 years old specimens! Flowers are zygomorphous (bilaterally symmetrical), of a maximum length of 7.5 cm, reddish to bright scarlet in colour and have white hair on the tube. Floral tube usually curved and slightly dilated above the pericarpel, which bears small appressed scales. The flower open sufficiently widely so that the stigma and red stamen filaments are visible from outside. Anther exerted at least 10 mm beyond the tube.

Ribs

15 to 30, parallel straight, slightly undulate, broad basally up to 1 cm tall.

Stem

The plant's diameter ranges from 15 to 30 cm, the stem colour varies from pale green to dark green

Radial Spines

8 to 10, brownish-red becoming grey, awl shaped and slightly curved, very different in young and old plants. There is also a form ("flavispina") with orange-yellow spines.

Fruits

Globose, dry at maturity, dehiscent with tuft of short hair-like spines.

Areoles

Well spaced at first, later confluent. Flower producing areoles often bears many long bristles and up to 7 cm long spines.