Al Schneider's Rocky Mountains Plant Descriptions

Brittle Prickly Pear
Opuntia fragilis
Cactus family (Cactaceae)

Fragile Prickly Pear is a low growing, spreading cactus with large showy yellow flowers. The pads (stems) are usually small, potato-shaped, and flimsily jointed ("fragilis") so that the pads easily attach themselves to passing animals and thus spread widely. This plant is easily confused with Whipple's Cholla (Cylindropuntia whipplei), especially when the plants are young. Colorado flora authority William Weber indicates, "Probably a great amount of the variability of [all] Opuntia is related to hybridization between this and other species." Thomas Nuttall collected this plant in Minnesota, probably in 1810. He named it Cactus fragilis in his 1818 " of North American Plants", and the plant was renamed Opuntia fragilis by Adrian Haworth in 1819.


©2011 Tony Frates

Description

Plants mat-forming, 2-4" tall, to 3-4' wide. Joints from 1/3" long, 1/2-2" wide, to to , blue green, easily detached. in most or lacking, usually 1-9 per , oriented in varying directions, to 1+" long, angled or somewhat flattened. tan to brown. Flowers to over 2" long, yellow, bronze, or violet. dry, tan, with or without .

Field Marks

Low mat of spiny, potato-shaped pads, large usually yellow flowers.

© Al Schneider

areoles are small light or dark-colored bumps in cactus containing spines. Areoles are also island-like pieces of lichen.

spine -- a stiff, sharp structure formed by the modification of a plant organ that contains vascular tissue. A spine can be formed by a latteral branch, a modified leaf or a thorn.

ovate -- Oval, egg-shaped, with a tapering point.

orbicular -- Circular or nearly circular in outline.

fruit -- any seed-bearing structure in flowering plants. It is formed from the ovary after flowering.

obovate -- Teardrop-shaped, stem attaches to tapering point.

Glochids are tiny barbed hairs which grow from areoles of cacti. Cactus glochids easily detach from the plant and lodge in the skin, causing irritation upon contact.

genus -- A subdivision of a botanical Family in which all members have a significant number of similar characteristics.