Neolloydia
Neolloydia is a small genus of cylindrical, tuberculate cacti native to Mexico and the southern United States, distinguished by grooved tubercles and showy magenta to pink flowers. Once a fairly broad genus, it has been repeatedly whittled down by taxonomists — many of its former members have been transferred to Turbinicarpus and other genera — so that today Neolloydia is reduced to a mere handful of accepted species, as few as one in the strictest treatments and about three in current listings.
Description
Plants in Neolloydia are small and slow-growing, forming solitary or clustering cylindrical to shortly columnar stems. Like their relatives in the wider mammillaria alliance, the stems are built from spiralling tubercles rather than continuous ribs; a narrow groove runs along the upper surface of each tubercle, connecting the spine-bearing areole at the tip to the flowering point near the base. The tubercles carry clusters of stiff radial spines and one or a few longer, often dark central spines, giving mature plants a bristly, geometric look.
The flowers are the genus's showpiece — comparatively large, funnel-shaped, and a vivid magenta to purplish-pink, opening from near the stem apex in the warmer months. They are followed by small, dryish fruits containing black seeds.
Distribution
The genus is centred on the arid limestone country of northern and central Mexico, extending north into the Chihuahuan Desert of western Texas. Plants favour rocky, calcareous soils and gravelly flats among desert scrub, where they often grow half-buried and inconspicuous until they flower.
Like all cacti, Neolloydia is listed under CITES Appendix II, and wild populations should never be collected; nursery-raised plants are the only appropriate source for growers.
Notable species
- Neolloydia conoidea — the best-known and most widely grown species (formerly including plants once called N. texensis), a clustering desert cactus with pale radials, dark centrals, and bright magenta flowers.
- Beyond N. conoidea, current listings provisionally recognise Neolloydia inexpectata and Neolloydia matehualensis — obscure, poorly known plants of the conoidea complex whose rank, and even generic placement, remain debated.
Because the boundaries of Neolloydia have shifted so much, many plants once sold under this name are now placed in Turbinicarpus — for example the former N. gielsdorfiana, now accepted as Turbinicarpus gielsdorfianus; the synonym Cumarinia has likewise been folded into or around the genus in various treatments. When buying, it is worth checking the current accepted name.
Cultivation
Neolloydia species are grown much like other small Chihuahuan Desert cacti: give them a very free-draining, mineral-rich mix — ideally with added limestone or grit to suit their alkaline habitat — and plenty of bright light. Water thoroughly during the growing season only once the soil has dried out completely, and keep the plants cool and bone-dry through winter, which both prevents rot and encourages the following year's flowers.
These are slow, undemanding plants once their drainage and dry winter rest are respected. Overwatering and heavy, water-retentive composts are the commonest cause of loss. See Watering and Repotting for general technique.
In cultivation
Neolloydia is a collector's genus rather than a mainstream houseplant — it appeals to growers of small desert cacti who enjoy tubercled, free-flowering species. There are no significant named cultivars; interest lies in well-grown, symmetrical wild-type plants and in the genus's tangled taxonomic history. Propagation is usually from seed, though clustering plants can occasionally be divided or grown on from offsets.
See also
- Turbinicarpus — genus that absorbed many former Neolloydia species
- Soil and potting mix · Watering · Propagation — seed · Repotting