Britton and Rose, The Cactaceae vol IV, 260. 1923
What is Opuntia eburnispina?
Opuntia eburnispina is a rarely found prickly pear cactus from Cape Romano, Florida. It may be related to O. humifusa or O. austrina, and some botanists consider that O. eburnispina is synonymous with O. austrina.
O. eburnispina is prostrate, prickly pear, widely branched and forming mats on dune sands. It has tuberous roots. The pads are oval or suborbicular, varying to broadest above middle, thickish, 6 to 13 cm. long, pale green, somewhat shining, especially when young. The leaves ovoid-subulate, 4-5 mm long, pale green, recurved spreading. The spines relatively stout, 2-4 at an areole or sometimes solitary, 1-2 cm. long, ivory white with yellowish tips when young, becoming dark gray, not spirally twisted, greenish when wet.
Flowers are few; the ovary is obconic; the sepals are triangular, green, 5 to 7 mm. long. The flower is clear yellow, 4 to 5 cm wide. The petals are few, narrowly cuneate, often minutely pointed, and the berries obovoid about 2 cm. long or less. The seeds, at (ca. 3 mm), are smaller than those of O. austrina (ca. 5 mm).
Ploidy is unknown.