Chapistle

About

The coin-shaped leaves are the first thing you notice on this odd cactus. Flat, plump and almost perfectly round, they line woody, spine-studded stems and make the plant look like a small leafy shrub with cactus spines. It sits in the old, leaf-bearing branch of the cactus family, the group that kept true leaves instead of relying on a fat green stem, so its family ties show mainly in the spines and barbed bristles tucked at each leaf base.

In the Mexican lowlands it grows into a branching shrub, stout enough to be planted as a rough living fence, and it has the group’s unusual need for warmth, moisture and feeding. It is related to the grafting-stock Porter’s pereskiopsis, sharing that plant’s speed and ease, but its rounded foliage makes it the prettier of the pair to grow for its own sake.

Warm, bright and generously watered, it grows fast and responds well to pruning, so you can keep it as a tidy little bush. If it gets too cold or too dry, it drops its leaves and waits for better conditions. The one thing to respect is the fine barbed glochids at every leaf base, which make casual handling painful.

Appearance and character

Its leaves are flat, plump and close to circular, a fresh coin-green, ranged along woody brownish stems, so the whole plant looks like a leafy, round-leaved shrub instead of a cactus.

Beneath each leaf sits an areole carrying longer spines and clumps of fine, barbed glochids, the family’s defining cactus feature hidden among the foliage.

Given room it branches into a spreading shrub of a metre or two, and it responds well enough to pruning that it can be held to a neat, bushy shape or trained up as a rough hedge.

Flowers rarely show indoors; when they come they are yellowish, opening on older stems and now and then setting small fruits, but it is the round leaves that carry the plant.

Where it is from

Pereskiopsis rotundifolia is native to the seasonally dry Mexican lowlands, where it grows as a branching, spiny, leafy shrub through scrub and thicket and is sometimes set as a living fence. Warmth, bright light and a distinct rainy season are its normal conditions.

That habitat explains its care. Warmth and strong light suit it, with a generous supply of water and feed while it is in growth, and a rest with dropped leaves when it turns cool or dry. It cannot take cold, and it grows best kept warm, bright and moist through the warm months.

How it grows

In warmth, with light, water and food, it grows quickly and bushily, producing branches and leaves in no time, then pauses or sheds its leaves when it turns cool or dry. Warmth drives the growth, and it almost stops below about 12 deg C.

Pot it in a fast-draining but moisture-holding, fairly rich compost, and, quite unlike a desert cactus, keep it evenly moist and fed while it is warm and growing. Cut the water back when it cools.

Stand it in bright light with a little direct sun and steady warmth above about 12 deg C, and prune whenever you need to keep it bushy. Wear gloves or use tongs because of the glochids. It roots readily from cuttings, so bulking it up or starting again is easy.

To propagate, take stem cuttings; they strike fast in warmth.

Through the seasons

Spring brings it back into bushy growth as the warmth returns. Start watering and feeding generously again, prune to shape, and take cuttings.

Summer is its fast season. Hold it warm, bright, evenly moist and well fed, and it branches and leafs up rapidly.

Autumn winds it down as light and warmth fade. Ease off the water and feed.

Winter is a cooler pause above about 12 deg C. Water sparingly, expect some leaves to drop if it is cool, and keep it warm and bright to hold the rest.

Care difficulty

Easy and quick in warmth, with handling the only real chore. Like its relatives it needs generous water and feed in warm growth, and it falters, dropping its leaves, only when kept too cold or too dry. Warm, bright, moist and fed, it grows quickly and prunes easily. The barbed glochids, though, make it a plant to handle carefully.

Watering

Once the top of the compost begins to dry, water it, and keep it evenly moist right through its warm growing season, since this leafy cactus is far thirstier than a desert one. Let it bake dry while warm and growing and it will shed its leaves.

When it cools, water less and let the compost dry further between drinks, and keep it on the dry side through a cool winter rest, when a cold, wet pot rots the roots. It is cold and wet together, not water in itself, that does the harm.

Warning signs, diseases and pests

Dropped leaves usually say the plant is too cold or too dry. Keep it above about 12 deg C and evenly moist while growing, and the leaves stay put.

A base that softens and blackens is root rot from cold, wet compost; warm it up, dry it out, especially in winter, and root a sound cutting if the base is gone. Mealybugs and scale settle on the stems and yield to dilute alcohol or a horticultural oil.

The glochids are the grower’s problem more than the plant’s. Handle it with gloves or tongs, since the fine barbs bury themselves in skin and are a nuisance to dig out.

Growing environment

Bright light with a little direct sun supports strong, fast, leafy growth; in a dim spot it grows thin and drops its leaves. It needs brightness, though it tolerates a touch less sun than a desert cactus.

Warmth is non-negotiable, above about 12 deg C, since this tender, tropical-climate cactus rests and sheds its leaves in the cold. It likes average to high humidity.

Grow it in a fast-draining but moisture-holding, fairly rich compost in a pot in a warm, bright spot, pruned bushy, and placed where its glochids cannot catch a passing hand.

Feeding

Through warm growth, feed it every couple of weeks to monthly with a balanced liquid feed, since this quick, leafy cactus needs more food than most cacti. Its pace depends on being fed well.

Taper off as growth slows in autumn, and stop over the cool winter rest. Fresh compost supports a newly potted or rooted plant through its opening weeks.

Troubleshooting

It is shedding its round leaves. Too cold or too dry. Keep it above about 12 deg C and evenly moist in growth to hold them.

The base has gone soft and black. Root rot from a cold, wet pot. Warm and dry it, above all in winter, and root a healthy cutting if the base has failed.

How is it different from Porter’s pereskiopsis? Its leaves are rounder, close to circular, and it makes a prettier, bushier plant, where Porter’s pereskiopsis is the leaner grafting stock. Both are fast, warmth-loving leaf cacti.

I keep picking splinters out of my hands. Those are glochids, the barbed bristles at each areole. Use gloves or tongs; they lodge in skin and resist removal.

Is it safe around pets? Chemically, yes, since it carries no listed toxin. The caution is physical, from the glochids and spines, so keep it out of a pet’s reach.