Back in my ol’ greenhouse, figuring out what to write for this weekend’s article was a no-brainer – it would have to be a feature on some truly special plants, the arachnid haworthias and their allies. Fortunately, my attraction to spiders isn’t just limited to the animal kingdom, and I have a few wonderful examples of "plant spiders" to show for. Haworthia arachnoidea (meaning "spider-like") is one of the gems of the genus, to the extent that a few growers worldwide concentrate on this species alone and specialize in growing as many different forms and variants as possible. The cobweb imagery suggested by its name is derived from the overall appearance of some of the forms. Generally, the leaf margins and keels are lined or covered with numerous whitish hairs, which vary in length, density, rigidity and width. As you can see from some of the pictures here, some of the forms really look like dense and intricately-patterned spider’s webs.
Still, others look at the sword-like green to blackish-green leaves of the species with the protruding marginal hairs or spines and see a resemblance – not to spider’s webs – but instead to the spiny legs of a spider. H. arachnoidea and its variants are found exclusively in South Africa, mainly along the western cape province surrounding Capetown. It is quite a variable plant, not just in terms of the density and texture of its hairs and teeth, but also in terms of its overall size and coloration. Hence, several varieties have been recognized by the experts. My favorite variant is the plant which some people actually mistake for a cactus because of its hard, spiny overall appearance – H. arachnoidea v. scabrispina.
Before I proceed any further, just a word on the photos for today’s article. These are obviously not the high-quality artistic pictures of Johann Espiritu which you have grown accustomed to. I simply forgot to schedule a photo shoot with Johann this time around, and by the time I remembered about the upcoming article, it was really too late to get into Johann’s busy lawyer schedule. So I winged it this time around. Fortunately, I have one of Johann’s old Sony Cyber Shot digital cameras with the Carl Zeiss lenses, which sure made my photographic efforts that much easier.
Getting back to scabrispina, I have featured three clones of this special plant. Two are more typical scabrispina and are found in Koup Station, Laingsburg, South Africa. These vary in the length and coloration of the leaves and the density of the spination. The third clone is much less spiny than the other two. It also shows affinities to another great Haworthia rarity, H. marumiana v. dimorpha, with flowers similar to the latter. The spines on these plants are quite stiff and, if one pressed in the wrong direction, can actually draw blood. This is the hardest spined of all known haworthias, and is much coveted by collectors.
Another especially beautiful plant featured is the form of H. arachnoidea v. setata with very dense white hairs all over the plant, giving this form a truly spider web appearance. It, too, is much sought after. Other variants featured are the more typical variety arachnoidea and the variety aranea with more slender leaves and very fine small hairs all across the leaf margins and keel. You may have already noticed by now the one plant which doesn’t much resemble a spider and isn’t hairy or spiny at all – the form of H. arachnoidea v. nigricans featured here. Well, not all spiders are that hairy, after all. And in the plant kingdom, some forms of arachnoidea are quite glabrous and have no spines or hairs whatsoever. Of course, v. nigricans is also quite variable in the wild, and there are forms which are also well-toothed but still much less than the other variants.
There are other Haworthia species (I call them arachnoidea allies) with representatives which may also be classified as arachnid-lookalikes. This is especially true for some of the forms of H. bolusii featured here which also possess that cob-webby quality. The difference lies in the overall coloration of the leaves and the level of translucence found on the leaf tips and margins. H. bolusii has an overall bluish-green coloration and has quite significant translucence on its leaves. H. arachnoidea has no translucence on its leaves. H. semiviva, which was previously described as a variant of bolusii, is also a special spider plant. In the wild, its leaf-tips dry up and wrap around the plant’s body, forming an added protective sheath against the sun. H. decipiens, another species, also has members with the spider-look, principally in the form of v. xiphiophylla (which used to be classified as an arachnoidea variant until just last year). And then there’s that all-time cutie, H. translucens v. tenera, the littlest hairy spider.
Ingo Breuer, a blossoming German botanist (and also a technology expert with SAP Germany in his day job), has studied haworthias quite extensively, both in the wild and in his greenhouses. He has proposed the recognition of several new haworthia species, and a few of them are candidates for plant spider of the year. Those featured here are H. tretyrensis (which was previously thought to be a form of xiphiophylla); H. jansenvillensis (which others recognize as H. decipiens v. virella), which is a large-growing decipiens-like plant; H. odetteae which is particularly hairy and was once thought to be a variant of H. bolusii; and the very beautiful H. devriesii, one of the newest haworthias to be discovered. I am especially attracted to H. devriesii because of its bluish-brown coloration and the wonderful "windows" or translucence of its leaves. It is an extremely rare plant at this time, not known in worldwide collections just yet. I was fortunate to get a couple of plants from its discoverer, Vincent de Vries whom I have been dealing with for the past five or so years. I nicknamed my plant the "white spider."
Careful watering year-round and a very porous growing medium are requirements for growing these plant spiders well. I find it is also best to grow these plants in half-shade in order to prevent the leaf tips from drying out excessively. Of course, the more you water, the more direct sunlight these plants can withstand, but I’d rather water less than risk over-watering and rotting the plant altogether. I would prefer you water at the growing medium only, not on the plants themselves. I have seen plants rot from excess water lying around their tight leaves. If you want to get the grime and dust off the leaves of your plants (something we have to fend off regularly in Metro Manila pollution), I would advice using a fine mist spray instead of watering the plants overhead. These arachnid haworthias are beautiful collector’s items and are well-worth a try in your greenhouses or sunny windowsills. But I hope that one day soon, I’ll have a few big hairy members of the "animal-persuasion" under my roof as well.
Maybe even a Bulacan Tarantula.