Haworthia glauca v herrei
The Haworthias are a remarkable group of succulent plants originating from southern Africa, closely allied with Aloes, Astroloba, Gasteria, and Poellnitzia. The Haworthias are leaf succulents, typically producing tight rosettes of spiraling leaves. Plants may be virtually stemless, producing a compact rosette, reminiscent of Sempervivums, or may produce short stems, with columns of leaves in tight spirals. The majority of species produce multiple offsets, sometimes producing large clusters of dozens (or hundreds) of rosettes in compact mats, although some species are slow to offset, and may remain solitary for much of their lives. The leaves vary in texture, patterning, and frequently bear raised dots, lines and ridges; some of the most striking examples of this can be seen in Haworthia limifolia, and H. reinwardtii (one of several species bearing the moniker of “Zebra Plant”)
My references are a bit dusty now, and are out of date, but these estimated the total number of Haworthia species at about 125. The article in Wikipedia states that B. Bayer recognizes approximately 60 species in a review of the genus in 2012, while acknowledging that other experts suggest a more generous figure. Numbers of species aside, there are a huge number of named varieties and an ever increasing list of cultivars as well. All are interesting plants, and virtually all are quite attractive. The small size of most plants and their relative ease of culture make them particularly popular with succulent growers.
Haworthia glauca is widely distributed from the central to western portions of the Eastern Cape region. It typically grows fully exposed or under only slightly shaded situations on rocky slopes in habitat. Most of the plants of the species produce smooth leaves to slightly tuberculate leaves; in variety herrei, the leaves are typically more conspicuously tuberculate as can be seen in this image (this trait is not evident in my plant). The leaves are quite rigid, and end in a sharp tip, making plants of this species one of the very few of the Haworthias which can be described as “prickly”. Even without the typical ornamentation of windowed leaf tips, tubercles, etc. this is an attractive species, with glaucous grey to bluish foliage produced in tight spirals on stems which may grow to nearly 10 inches tall. Plants typically ramify from the base, producing tight cushions of many clustered stems. Habitat photos of some truly remarkable plants will give some indication of the ultimate size and spread of this plant, but be warned, I have found this plant to be a very slow grower, so the prospects of growing an equivalent plant, even under ideal greenhouse conditions, will require many years – and possibly decades of growth.
As with all Haworthias, the flowers are produced at the ends of tall (to about 16 inches on my plant) wiry stems and are small and rather inconspicuous, with whitish petals with greenish to greenish brown midribs. Detailed images of the flowers reveal that 2 of the petals are recurved to produce Labellum – a trait which is present in a good number (although not all) species of Haworthia.
As with most Haworthias, this variety has proven to be be easy to grow. While it will tolerate a reasonable amount of shade, its habit of growing in mostly unshaded conditions suggests that it will require more light than most Haworthias for optimum growth. I move my plant outdoors in spring once temperatures allow, and gradually acclimatize my plant to full sun, where it remains until I move my plants indoors again in fall. It responds well to my guidelines on growing cacti and other succulents. While warmer temperatures would be appreciated, this plant has survived temperatures to the 40’s and upper 30’s in my care. It is a nice compact plant, although it may not be as overtly decorative as some of its relatives, it is still a very attractive plant, and will not quickly outgrow its allotted space. I believe that this plant is non-
In the years that I have been growing this plant, I have seen no evidence of insect infestations – I suspect that under hotter, drier conditions in the greenhouse, spider mites could be of concern, but I have never observed issues with my plant, This has proven to be a very forgiving, and tough survivor – but I believe that this plant should be provided with brighter and drier conditions that its softer leaved cousins (such as Haworthia cooperii, and H. attenuata).
This hasn’t always been the easiest plant to find in the trade; to date, I have never found it in any of the local nurseries, and very few of the mail order nurseries which I have dealt with over the years regularly carry it. I believe that it has been offered through Mesa Garden, Out Of Africa, and possibly Arid Lands: plants may occasionally be offered through annual cactus and succulent society sales, and may also be available through the International Succulent Introductions of the Huntington Botanical Gardens.