Aloe comosa

A tall rare aloe from South Africa's winter-rainfall west

Aloe comosa is native to a small area around the Olifants River Valley north of Clanwilliam in South Africa's Western Cape. A single trunk carries a substantial crown of blue-green leaves and can eventually support an exceptionally tall flower spike.

The species grows in hot, open country near the boundary of the Ceres Karoo, within a climate where most rain falls in the cooler season. Summers are intensely dry and exposed, and the mineral ground releases water quickly. Smooth recurving leaves and a sturdy stem persist through these strong seasonal contrasts.

Growing succulents in containers

Repotting

Repot Aloe comosa when the container distorts, the root mass has no room, drainage becomes uneven or the plant repeatedly tips over. Support the crown while freeing the roots, cut only dead material and preserve the central root mass.

Watering

Allow Aloe comosa a clear dry interval, but water thoroughly when the root zone has dried and the leaves remain firm. Permanently moist substrate invites root and crown damage, while extreme dryness leaves the rosette thin and slow to restart.

Light

Aloe comosa needs strong daylight and tolerates direct sun after a gradual introduction. Keep it on the sill of a large east, south or west window, not several metres away.

Temperature

Do not leave the rosette pressed against winter glass or in the path of cold ventilation.

Fertilising

Give Aloe comosa a complete fertiliser at the low end of the product-label rate during active root and leaf growth. Feeding can continue outside summer only if strong light and warmth keep the plant visibly growing.

Handling and leaf care

Give the larger rosette of Aloe comosa generous side clearance and move it by holding the pot. Keep the rosette clear of passing hands and neighbouring pots.

Problems on a larger, stem-forming Aloe comosa

• Old lower leaves dry into a skirt below the crown: Gradual drying from the lowest leaves is normal as Aloe comosa develops a stem. Remove a leaf only when fully dry and loose; rapid collapse moving upward toward the crown points to root or stem trouble.
• The crown becomes narrow, floppy or one-sided: A large rosette needs very bright, even light. Acclimatise it to a brighter site, rotate the pot and make sure the tall plant is stable rather than burying the stem more deeply.
• Brown colour develops evenly on firm exposed leaves: Bronzing can be a normal response to strong sun or dryness. Distinguish it from scorch, which creates bleached, sharply bounded or papery tissue after a sudden light increase.
• The stem base darkens or the crown pulls free: This signals serious rot rather than ordinary lower-leaf ageing. Stop watering and inspect the stem and roots; cut above all discoloured tissue if a sound crown can still be rerooted.
• A tall flower stalk appears and the rosette pauses: Flowering is normal and may temporarily slow leaf production. Support the stalk if needed, but do not compensate with extra water while the pot is already damp.

Aloe comosa is toxic to people and pets

• Keep this plant away from children, cats and dogs, and handle the leaf tips carefully.
• The leaf latex contains anthraquinone glycosides that can irritate skin and the digestive tract. Rigid tips and toothed margins can also scratch or puncture.
• Swallowing the latex may cause an upset stomach, while skin contact can cause irritation. Contact a veterinarian or medical professional if symptoms develop.

The meaning and history of Aloe comosa

Aloe comes through Greek aloe, an old name for the bitter plant juice, itself borrowed from a Semitic language. The Latin epithet comosa means tufted.

Carl Linnaeus established the genus Aloe in 1753 in Species Plantarum, page 319.

Hermann Wilhelm Rudolf Marloth and Alwin Berger first described Aloe comosa in 1905 in Botanische Jahrbücher für Systematik, volume 38, page 86.