Opuntia fragilis / brittle pricklypear

Adjectives: clonal, drought tolerant, exposed, nasty, native, nutrient poor soils, rocky

Also known as: little pricklypear, fragile pricklypear, pygmy pricklypear, pygmy tuna, potato pricklypear
See also: Opuntia polyacantha / starvation cactus

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When we think of cacti, we often think of hot deserts… not of plants that can survive extreme cold nearly at the Arctic Circle. Well, think again… here it is: the one that grows farther north than any other cactus. In addition to all of the west, its range extends east to Michigan and south to Texas.

The brittle pricklypear is a perennial native mat- or clump-forming cactus, rarely more than 4 in high. As such, it is the smallest of the opuntias but the mats often exceed a foot in diameter. The individual, potato-shaped pads or cladodes (modified stems) are easily detached from each other, often just by bumping the plant… hence the name “brittle”. Aereoles (small projections) on the pads give rise to 2-7 spines (modified leaves). Rarely, they make it to an inch long. They are not hooked but the areoles also have tiny barbs (glochids) at the base of the spine cluster. These easily detach and embed in things, i.e. in you. These can be painful and hard enough to see that they’re hard to get out of your hand… or other body parts, should you be so unlucky.

The flowers are solitary and up to 2 inches across. They can vary in color from bright magenta to soft yellow to greenish-yellow. They can be difficult to photograph, however, because brittle pricklypears seldom flower. When they do, the flowers look more or less like those of Opuntia polyacantha (starvation cactus).

Brittle pricklypear fruits are pear-shaped and small… less than an inch long. But they happen even less often than the flowers. They are usually spiny. Interestingly, they are also technically berries. Though this cactus does produce seeds that are spread by small mammals and birds, the main mode of reproduction is by fragmentation and rooting. Indeed, the pads can root even in the absence of water.

Like many (but not all) desert cacti, brittle pricklypear grows from a shallow, fibrous root system. It occurs in a variety of desert, grassland, prairie, and woodland communities, but not as a dominant species. It is tolerant of most soil types, including saline and alkaline. It is, however, shade intolerant and may decrease on good sites when overtopped by other plants.