Matucana krahnii
| Light | Bright light; full sun with a little shade in the hottest months |
|---|---|
| Water | Regularly through the growing season, letting the soil dry between waterings; keep dry and cool in winter |
| Soil | Fast-draining mineral mix (see Soil and potting mix) |
| Temperature | Keep above freezing; roughly USDA zones 9b–11 |
| Propagation | Seed; offsets where produced |
| Toxicity | Non-toxic to cats and dogs |
Matucana krahnii is a small cactus from northern Peru. It forms a flattened-spherical to short-cylindrical stem — one of the more globular members of its genus rather than a tall columnar plant — clothed in curved, pliable, yellowish-brown spines that grey with age and topped in the growing season by the slightly zygomorphic (bilaterally tilted) crimson flowers whose tilted form is the hallmark of Matucana.
Description
Matucana krahnii grows as a green to grey-green stem, flattened-globular when young and lengthening only to a short cylinder with age — it does not become truly columnar as some of its relatives do. It reaches roughly 10–14 cm tall and 5–10 cm across. The body is ribbed and divided into low tubercles, the closely spaced areoles bearing curved, flexible spines that are yellowish-brown and grey with age; the longer central spines can reach several centimetres. Plants are usually single-stemmed, but older specimens may branch or offset from the base.
The flowers appear from areoles near the crown in the warmer months, often in several flushes. As in the rest of the genus they are tubular and slightly asymmetric — leaning to one side rather than opening as a perfect radial star — in deep crimson to red, sometimes with magenta tones, and the genus's zygomorphic flowers are pollinated in habitat by hummingbirds.
Distribution and habitat
The species is endemic to Peru, where the genus as a whole is restricted to the Andean valleys and slopes. Matucana krahnii grows north of Balsas, in the Amazonas region, on steep, gritty sandstone slopes at roughly 1,650–1,750 m, enduring strong sun, sharp drainage and a marked dry season. Understanding these conditions — bright light, lean soil and a genuine winter rest — is the key to growing it well.
Cultivation
Matucana krahnii is an accommodating grower by cactus standards, appreciating a little more water than desert globulars during active growth. Its roots are fine and rot-prone, so plant it in a very free-draining, mostly mineral mix and give it bright light — full sun suits it, though shading from the fiercest afternoon heat helps in very hot climates and keeps the spination looking its best.
Water thoroughly while the plant is in growth, allowing the mix to dry between waterings, then reduce and finally withhold water through the winter. A cool, dry winter rest both prevents rot and encourages the following season's flowers. See Watering and Repotting for general technique.
Propagation
Seed is the usual method and germinates readily on a warm, gritty surface kept humid until the seedlings establish; see Propagation — seed. Where a plant branches or produces basal offsets, these can be removed, allowed to callus and rooted as described under Propagation — offsets and Propagation — cuttings.
Common problems
- Rot — the main risk, almost always from overwatering or a slow-draining mix, especially during the winter rest; keep the plant dry and cool in the cold months.
- Etiolation — too little light makes the stem thin, pale and weakly spined; give it as much sun as your climate allows.
- Pests — mealybugs (white fluff in the areoles and on the roots) and red spider mites (fine webbing, bronzed skin) are the usual offenders. See Pests and diseases.
See also
- Matucana — the genus overview
- Soil and potting mix · Watering · Propagation — seed · Propagation — offsets · Repotting