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Hydnora africana, known also as Jackal food or Jakkalskos, is one of about ten species in the parasitic flowering plant family Hydnoraceae (Piperales), and is frequently referred to as one of the strangest plants in the world (e.g. Visser and Musselman 1986).  Species in both genera of this small family (genus Hydnora is limited to Africa and Prosopanche limited to South America) live most or all of their life cycle underground and do not make chlorophyll or have the ability to photosynthesize (Nickrent et al. 2002).  Instead, they derive all their nutrients from the roots of their host plants.  When describing H. africana to western science in 1774, botanist Carl Thunberg misinterpreted the angiosperm as a fungus due to its prolific hyphae-like system of roots and lack of stems or leaves (or even modifications of leaves) and bestowed it with the genus name Hydnus from the Greek Hydenon, meaning fungus-like (Voigt 2008; Bolin et al. 2011; Carlquest 2013).  

Native to and fairly common in the semi-arid Karoo-Nabib ecological region located along the southwestern coastal strip from South Africa to southwestern Angola, H. africana exists almost entirely as a root structure underground, entwined around and parasitizing the roots of its hosts: species in the genus Euphorbia (mainly E. gummifera, E. gregaria and E. mauritiana).  Hydnora africana, like the others in this family, has two types of roots: fast-growing, highly-branched “pilot roots” which seek out hosts (although there is evidence that these pilot roots may indeed be stems rather than root structures; Tennakoon et al. 2005, 2007) and stubby budding roots which appear to secrete growth factors that induce host roots to grow to them.  These “haustorial roots” form an attachment disc through which the parasite extracts fluids and nutrients from the root xylem of its Euphorbia host. Succulent portions of the pilot roots, if broken apart from the rest of the plant, can lie dormant for long periods of time without a host interaction; once they again hook up with an appropriate Euphorbia root the H. africana root fragment can propagate vegetatively into a new plant (Voigt 2008, Carlquest 2013).

The flowers also develop underground and after appropriate rainfall emerge as the only part of the H. africana plant to rise from its subterranean habitat.  Flowers branch directly off the pilot roots as fleshy, tri-lobed, slow-growing, brown spheres with bright orange insides and have a unique morphology and pollination ecology.  When first mature, the flower puts out a dung- or carrion-like stink to mimic a potential insect brooding site and attract dung beetle and dipteran pollinators.  A recent study finds that Hydnora africana elevates the temperature of the flower during blooming, probably to increase to volatility of the attractant odor, although also possibly to entice insect entry (Seymour et al. 2009).  The insect visitors find their way into the center of the flower by squeezing through dense fibers that hold together the barely-opened sepals.  As it is far more difficult to squeeze back out, the insects remain detained inside.  After several days during which the insect pollinates the flower and the anthers drop copious amounts of pollen, coating the trapped insects, the flower opens further and the insects are released to distribute pollen to other flowers (Bolin et al 2009; Carlquest 2013).

When ripe, the fruit of H. africana measures about 8 cm in diameter.  They have sweet, starchy flesh and up to 20,000 tiny seeds.  Birds and small mammals such as jackals, porcupines and moles eat the fruit and disperse the seeds.  The fruit shows up in local recipes, eaten simply roasted it is reported to have a texture and taste similar to potato.  The root is ground for various traditional medical purposes including diarrhea, dysentery, and acne, used as a tanning agent for fishing nets, and initial screenings show it have antimicrobial potential for modern medicine (Bisi-Johnson et al. 2010; Fox and Norwood Young 1982; Saadabi and Ayoub, 2009; Takhtajan 1997; Voigt 2008; Watt and Breyer-Brandwijk 1962).


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