araneispinus (also considered just a form of D. zehntneri) is
a squat tiny little solitary plant that - in culture - produces just
like D. boomianus many offsets.
Stem: Dull-green 10-20 in diameter and 7-10 cm tall.
Cephalium: Up to 1 cm tall and -4 cm wide, at the apex of the
plant, creamy-withe to light-brown with yellow to brownish bristles up
to 2 cm..
Ribs: About 20, somewhat spiraled, forming nipple-like tubercles
to 1 cm high.
Areoles: Oval, sunken, ca. 8 per ribs.
Radial spines: Interlacing, densely covering the plant, 10 to15
up to 1-2 cm long, pectinate, flexible spines creamy white or
whitish-yellow with dark tips, becoming pale-brown to whitish, recurved
backwards, sitting on the plant like spiders.
Central spines: None.
Flowers: White, scented, slender funnelform, up to 9 cm long. The
position of the stigma is at the top of the stamens. Each flowering
lasts only one night, but that night it produces many flowers.
Fruit: Club-shaped red 2,5 cm long. The plant produces seed-pods
twice a year, when it flowers.
This plant is part of the D. zehentneri
comprises several variable subordinates taxa, but not all are
universally recognized. Some authorities
recognize only the following :
subsp. zehntneri Usually globose and
completely covered in white thin, needle-like spines, the flower is
about 3 cm long and the fruit are red (Origin: Sentocé)
subsp. horstiorum Slow growing form = D.
zehntneri (Origin: near Minas do
Mimosa, Moreno, Sierra do Espinahaco, Bahia )
subsp. boomianus Usually disk -shaped, with dark tipped
yellowish spines, the flowers are up to 9 cm long (Origin: Sierra do
subsp. buenekeri This species does share the complex
commonality of tuberculate ribs and basal offsetting, but its white,
club-shaped fruit does not fit with the dark red , much elongated and
slender fruit of the other taxa.
subsp. araneispina has flexible,
interlacing spider-like spines that cover the plant.