Habitat: USA, in particular Northern Arizona.
Cultivation: -Glandulicactus are not easy to grow because they are very sensitive to mold and rot. Be careful not to water them too much and keep the plant in a well ventilated place, even during the winter rest.
Curiosity: The genus Glandulicactus, together with others, has been recently included in the genus Sclerocactus but, as always in these cases, there are different classifications according to the author of reference. It is therefore possible to find single species under different genera (for example, one can come across both the names “Glandulicactus uncinatus” as well as “Sclerocactus uncinatus”).
Navajoa is a genus of dwarf, rare cacti from northern Arizona, in the United States. It includes only two species: N. durispina and N. fickeisenii, though either the number of species and the classification of the entire genus is uncertain. Some authors suggest that the genus Navajoa should be part of the genus Pediocactus. Some other authors, instead, suggest that Navajoa is a separate genus including only one species with 2 or 3 subspecies instead of 2 species. The uncertainity in the attribution of names is typical of small genera of rare cacti. On the market, you thus may find the same plant named in different ways: Pediocactus sp. or Navajoa sp.
The natural habitat of Navajoa is the Grand Canyon area, where it grows in scattered populations along the Canyon edges close to Little Colorado and Colorado Rivers, in gravel-based soils. It is threatened by habitat destruction, illegal collection, trampling by large herbivores and grazing. Every species of Navajoa is rare and threatened in their native habitat: Navajoa is in fact one of the genera included in the Appendix I of the CITES convention. The CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora) is an international agreement between governments. Its aim is to ensure that international trade in specimens of wild animals and plants does not threaten the survival of the species. The appendixes are lists of plants with different degrees of protection. The Appendix I includes species threatened with extinction and provides the greatest level of protection, including restrictions on commercial trade.
Navajoa is rarely seen in cultivation, precisely because it is very rare. Its rarity is what makes it so sought after by cacti collectors. However, it is possible to cultivate it and still respecting its natural habitat: there is the possibility to propagate it either through seeds and grafting. To propagate it in the cultivated form can still prevent it from the complete disappearing, should it become extinct in its natural environment.
Navajoas are dwarf, globose, solitary cacti, that don’t exceed 6-7 centimeters of height and 5-6 centimeters in diameter.
Their stem is dark green and it is furrowed with tubercles so prominent that they look like nipples, at the top of which there are the areoles. The areoles are the typical buds in the Cactaceae family, from which the spines develop (in other families, usually leaves or branches sprout from buds). In the case of Navajoa, the areoles are creamy white and airy, and give birth to curved quills, also creamy white, with the consistency of cork. These peculiar thorns are hollow: that is to collect the morning dew. They may become intricate, as they are long (0,5-2 centimeters long) and curved.
Navajoas enter dormancy in Winter and show a brief vegetative growth season in Spring. During the Spring, blooming occurs.
Their flowers grow at the top of the stem in little groups of two or three. They are big if compared to the stem (2-3 centimeters in diameter), usually creamy-yellowish white in colour, with numerous petals and a central, yellow button formed by stamens and pistil (the reproductive organs of any blossoming plant, hosted in flowers). Flowers are borne on a scaly calyx, on which sepals (the scales) are of a dark, deep purple, with white edges.
VARIETY AND TYPES
Here below are the two accepted species in the genus Navajoa:
- N. durispina
- N. fickeisenii
Check our online shop to find them!
TIPS FOR GROWING
Navajoa is not the easiest cacti to cultivate, due to its susceptibility to rot and fungi. Here below are our cultivation tips:
- Navajoas need planty of direct sunlight and, more important, a good ventilation. Put them in a spot exposed to air drafts. In strong light, it tends to bronze and to produce healthy flowers and spines.
- It can tolerate temperatures to -15ºC if the soil is maintained completely dry. Pay attention, anyway: to stay safe, we suggest to keep it at at least 5ºC.
- It needs regular watering in late winter and early Spring, when it occurs the short main growing season, and also in Autumn. Instead, keep it completely dry during the Winter. During its dormancy, pay attention to the humidity of the air, that should be maintained low.
- During the growth season, fertilize with a product rich in potassium and phosphorous and poor in nitrogen.
- Repotting isn’t necessary, as this plant remains cvery small.
Propagation is usually carried out through seeds and grafting. To stay safe, we suggest to graft at least the first individual, to ensure the survival at least of one plant to produce seeds. Germination is actually difficult: scarification is the best method to enhance it: it’s about to remove the external peel from the seeds before planting them. The optimal temperature for germination ranges from 17ºC to 35ºC, with a proper day length (13-14 hours). It has, anyway, a low rate of success. Grafting is definetely the most successfull method.