Consolea
Consolea is a small genus of tree-like opuntioid cacti native to the Caribbean and the extreme south of Florida. Unlike the sprawling, chain-of-pads growth most people picture when they think of a prickly pear, a mature Consolea builds a single woody trunk topped by a crown of flattened, jointed pads — giving it the unmistakable silhouette of a spiny little tree. Several species are rare or endangered in the wild, and the genus is a favourite among collectors who enjoy the more unusual, arborescent side of the opuntioids.
Description
Consolea species are shrubby to tree-like cacti that typically develop a distinct, cylindrical woody trunk before branching. From the top of that trunk they produce a crown of flattened, elongated pads (technically cladodes, the same modified stem segments seen across the opuntioids). The pads are usually thinner and more strap-shaped than those of a typical Opuntia, and they tend to be borne more or less in one plane, giving a flattened, fan-like crown.
Spines are highly variable between species — some plants are strongly armed with long, needle-like spines from the trunk and pads, while others are comparatively sparse. As with all opuntioids, the areoles also carry glochids: tiny, barbed, easily detached bristles that lodge painfully in skin and are a nuisance to remove, so the plants are best handled with thick gloves or folded newspaper.
Many Consolea are functionally dioecious or have a tendency toward separate male and female plants, which is unusual in the cactus family and can complicate seed production in cultivation. Flowers are typically yellow to orange or reddish, followed by fleshy fruits.
Distribution
The genus is centred on the West Indies. Species occur through the Greater and Lesser Antilles — Cuba, Hispaniola, Jamaica and Puerto Rico — as well as the Bahamas, with Consolea corallicola reaching into the Florida Keys at the northern edge of the range. Typical habitats are coastal and lowland: limestone (karst) outcrops, dry thornscrub, hammock margins and rocky, well-drained ground, often within reach of salt spray.
Several species are seriously threatened in habitat by land clearance, hurricanes, invasive pests and, in Florida, the introduced cactus moth (Cactoblastis cactorum), whose larvae bore into opuntioid pads. Wild populations of some species number only a handful of plants. Like the entire cactus family, Consolea is listed under CITES Appendix II, and wild collection is not appropriate; nursery-propagated material is the responsible way to grow these plants.
Notable species
- Consolea rubescens — the "road-kill cactus," a widespread and relatively vigorous tree-form species from Puerto Rico and the Lesser Antilles, often grown as an ornamental.
- Consolea corallicola — the Florida semaphore cactus, critically endangered and reduced to tiny natural populations in the Florida Keys.
- Consolea moniliformis — a Hispaniolan species with a slender, jointed, tree-like habit.
- Consolea spinosissima — a heavily armed Jamaican species, as the name suggests.
- Consolea macracantha — a Cuban species noted for its long spines.
Cultivation
As tropical and subtropical plants, Consolea want warmth above all — they resent cold and are unhappy below about 10 °C, so outside frost-free climates they are best kept as protected greenhouse or conservatory plants and brought in for winter. Give them the brightest light you can provide; strong light keeps the trunk sturdy and the pads compact, whereas too little produces weak, etiolated growth.
Grow them in a free-draining, largely mineral mix and water generously during warm active growth, always letting the mix dry appreciably between waterings, then keep them much drier and warm through winter. Because they naturally build a trunk and a top-heavy crown, larger specimens often need a deep, stable pot (and sometimes a stake) to stay upright. See Watering and Repotting for general technique, and handle every plant with respect for the glochids.
Propagation
The easiest route is vegetative: a detached pad or short jointed section, allowed to callus for several days and then set in a barely-moist gritty mix, will usually root and go on to form its own trunk. This mirrors propagation across the opuntioids — see Propagation - cuttings and Propagation - offsets.
Seed is also possible, but because a number of Consolea tend toward separate-sexed plants, setting viable seed often requires both a male and a female plant in flower at the same time; see Propagation - seed for general method. For rare or slow species, some growers speed things along by grafting onto a more vigorous opuntioid stock.
Common problems
- Rot — as with most cacti, cold-and-wet conditions in winter are the main killer; keep the mix dry and the plant warm during dormancy.
- Etiolation — insufficient light produces pale, weak, over-stretched pads and a floppy crown.
- Cactus moth and borers — Cactoblastis cactorum and other pad-boring pests are a serious threat, especially in the Americas; inspect for hollowed, oozing pads.
- Scale and mealybugs — the usual sap-sucking suspects hide in areoles and pad joints; see Pests and diseases.
See also
- Opuntia — the classic prickly pears, close relatives
- Opuntioid cacti — the wider group
- Consolea corallicola · Consolea rubescens
- Grafting · Soil and potting mix · Watering · Propagation - cuttings · Pests and diseases