GARDENER'S READING ROOM
Indoor Plants

Beyond The Big Tropical Leaf

Five years ago, when I first climbed into the truck of Fleetfoot & Foulweather, my heart beat faster and I knew my paycheck was in trouble. I had been a cactus collector for eons, but their stock amazed me. Then came Courting Frogs Nursery. Best known for zany little carnivorous plants, they also grow awesome cacti and succulents…. Last year, with our cactus and succulent collection maxed out of available space, Oasis Rare Plants showed up with their collection of caudiciforms. Well, I made room! With them and our other local specialty growers, Sky has one of the finest retail collections of cactus and succulents around, considering our space!

I can only brush the surface here, but I want to give you a better appreciation of the world beyond the Big Tropical Leaf. Some succulents are the size of a pin head, some the size of a tree! Some live underground with "sun roofs" through which light passes. Most people think the plants look bizarre, and they do. But the strange shapes of the plants help them adapt to unfriendly environments, conserve water and reduce transpiration (that's the plant equivalent of sweating).

A succulent is any plant that stores water in its leaves, stems or roots - including cacti, euphorbias, crassulas, agaves, milkweeds, lilies, and over 1000 species of "living rocks." In stem succulents, which most cacti are, the stem has at least partly taken over the leaf's function of photosynthesis. Root succulents store water and food reserves in the root.

Cacti include: 1) plants with leaves (e.g. Pereskia); 2) plants that produce leaves but lose them very soon (e.g.Opuntia); 3) plants with scale-like leaves or no leaves at all (e.g. Mammillaria); or 4) plants with "cladodes", stems resembling leaves (e.g. Schlumbergera, the Christmas Cactus). (The cladodes developed as a result of cactus migrating to forests where they received more moisture and semi-shade.)

Unique to cacti are small, usually wool-covered, "pincushions" on the stem ribs called areoles. Areoles bear spines and often flowers or shoots. Some cacti have hairs or sharp, barbed structures called glochids instead of spines. Cactus flowers are large and showy but last only a few days, as they represent a major loss of water for the plant. Because cactus spines are attached only to the areoles, tearing one off does little harm to the plant. In contrast, tearing a spine from a succulent can damage the tissue beneath. Another distinguishing feature is that cactus juice is usually watery and colorless. The sap of succulents varies - clear, sticky, or milky and irritating, like that of euphorbias.

Then we come to the caudiciform succulents. Ah, the caudiciforms! They store water and food in their roots, which are often turnip-like or tuberous. The root system can be very extensive; sometimes the roots grow close to or over the soil surface . On vining caudiciforms such as Sea Onion (Bowea) you may see the vines but not the root. Or you may see the root, but think it is a trunk or stem, as in Beaucarnia recurvata, the Pony Tail Palm.

Each species of succulents is different, so I can't really generalize on their care except to say that while the plant is actively growing, give it regular water. When it is dormant (and some go dormant in the summer), cut way back on the water – giving it just enough to keep it alive.

Stop in to see our selection. There is always something interesting going on.

By Mary Ann Greco
Skylights Autumn 2006, Vol 21, No. 3

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