Aloe comosa

Where the Clanwilliam aloe grows

Aloe comosa is native to a limited part of South Africa’s Northern and Western Cape, especially around the Cederberg and Olifants River region. It grows on hot, dry rocky slopes inland.

Its range is small, and the species is currently classed as Least Concern. Slow growth means wild collecting can still reduce local numbers.

Long-term care as Aloe comosa grows taller

• Sun: Give this species the brightest position available, ideally with long periods of direct sun. Rotate a young plant occasionally so the trunk and crown develop evenly.
• Water: Once the mix has dried completely, soak the pot thoroughly. Large containers can stay damp in the centre for longer, so wait for the deeper mix to dry and for the pot to feel lighter before watering again.
• Heat and temperature: The species comes from very hot, dry habitats and handles high temperatures well. Keep a potted plant frost-free. In a cooler bright room, let the mix stay dry for longer.
• Humidity: Typical dry indoor air suits this species. Keep air moving around the crown and water at soil level.
• Potting mix: Choose a deep succulent mix that drains quickly and contains plenty of grit or pumice. A heavy pot with a broad base becomes useful as the stem gains height.
• Feeding: A small dose of balanced succulent fertiliser during fresh growth is enough.
• Repotting and space: Repot when roots fill the container, drainage slows or the plant becomes top-heavy. Plan ahead for enough floor space and room above the plant as the trunk grows.

Problems that can affect the crown, stem and leaves of Aloe comosa

• New leaves become narrow and the crown leans towards the window: The plant needs more light to stay upright and compact. Move the plant into stronger sun gradually and rotate the pot as fresh leaves develop.
• The stem remains firm and the plant feels unstable in its pot: Its crown is now too heavy for the current container. Choose a wider, heavier pot and repot the plant firmly in fresh, fast-draining mix.
• The stem base darkens and feels soft: Excess moisture around the base of the stem has caused rot. Remove the plant from the pot promptly and inspect the stem base. Trim rotten roots and soft parts of the stem with a disinfected blade until healthy tissue is visible. Discard the removed material and allow the cut areas to dry before potting the plant in fresh gritty mix.
• Small brown shells or sticky residue appear on leaves: Scale insects may be feeding on the crown. Separate the plant from nearby plants and remove visible scale. Use a scale treatment and repeat it only when the label tells you to.
• New leaves emerge with hard, uneven swellings: Aloe mite is possible. Keep the plant apart from other aloes. Trim away the affected new growth using a disinfected tool. Stop once healthy tissue remains, then dispose of what was removed.

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.