Hydnora africana | |
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Flowers, Karasburg Constituency, Namibia | |
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Partially opened flower, near Robertson, South Africa | |
Scientific classification ![]() | |
Kingdom: | Plantae |
Clade: | Tracheophytes |
Clade: | Angiosperms |
Clade: | Magnoliids |
Order: | Piperales |
Family: | Aristolochiaceae |
Subfamily: | Hydnoroideae |
Genus: | Hydnora |
Species: | H. africana |
Binomial name | |
Hydnora africana | |
Synonyms [2] | |
Hydnora africana is an achlorophyllous plant in the subfamily Hydnoroideae, native to southern Africa that is parasitic on the roots of members of the family Euphorbiaceae. [3] It is also called jakkalskos or jackal food. [4] The specific epithet africana means from Africa. [5] Molecular data has suggested that Hydnoroideae is a "basal angiosperm" solidifying its place among the more primitive flowering plants. [3] Hydnoraceae are the only angiosperms known to have no leaves or scales and are considered obligate parasites, completely dependent on their hosts to survive. [6] The plant grows underground, except for a fleshy flower that emerges above ground and emits an odour of faeces to attract its natural pollinators, dung beetles and carrion beetles. [7] The vegetative body of the plants has been reduced to consisting only of roots and flowers. [6] The flowers act as temporary traps, retaining the beetles that enter long enough for them to pick up pollen. [3]
The vegetative parts of this plant are more similar in appearance to a fungus than a plant. [8] These plants do not have chlorophyll and do not perform photosynthesis. They obtain their nutrients entirely from a host plant, such as a species of Euphorbia . The plant is composed of thick succulent roots with no stems and the flower develops on surfaces of the host's roots. The flower is used as a temporary trap in order to facilitate pollination. [9] H. africana has an enzyme which allows it to dissolve some of the roots of its host plants in order to attach to them. H. africana attaches to the roots of the host and takes some of the nutrients that it makes from photosynthesis. [10] The flower has a succulent and thick texture, the portion that appears above ground is tubular with three openings. [3] There are three structures botanically named perianth segments which can be compared to sepals that unite at the top of the flower. [3] It has a fleshy peachy-orange flower that emerges from the ground after a heavy rainfall. [5] The flower is where the perianth segments join and a short tube is present. The anterior portion of the tube there are yellowish-orange structures extend into the tube, these are the anther groups. [3] These groups of anthers are held in bunches and are used as the flowers stamens. The anther groups are arranged into a triangle so that a gap forms between their pits and the beetles will proceed to fall down onto the stigma of the parasitic plant. [3] The basal portion of the flower there is a cavity that houses the white ovules that will mature into seeds. [3] Insects that pollinate the flowers do so by burying themselves in the sepals of the flowers through the very strong fibres that hold the sepals together. After the insects have been in the flowers for a couple of days, the flower emerges and opens releasing the insects to spread the pollen to other flowers in the area. [10]
Hydnora africana produces a fruit that grows underground, taking up to two years to ripen fully. The fruit is similar in taste and texture to a potato. Among other uses, it is used for tanning and preserving fishnets, because it is an astringent. [5] Each fruit produces about twenty thousand seeds. The fruit may be up to about eight centimetres (3 inches) in diameter. [11] Animals using the fruit as a source of food include, but are not limited to birds, baboons, smaller animals, jackals, porcupines, and moles. [4]
H. africana has a very strong and unpleasant smell. This smell is generated from the osmophores, which is a white spongy area on the inner surface of the tepals that eventually change colour to grey. Osmophores were first called "bait bodies" by Harmes. [12] Burger et al. concluded that the odour is made up of dimethyl disulfide and dimethyl trisulfide. These odours are also found in dead-horse arum, Helicodiceros muscivorus . [12]
Seeds from H. africana were brought back to the United States from Africa and planted in pots of Euphorbia. A flower of H. africana first appeared five and a half years after the initial sowing. [6] The rotting odour serves to attract dung beetles and other insects that then become trapped within the flower walls due to the stiff bristles. The trapped insects drop down the flower tube onto the anthers where pollen adheres to its body. It then falls farther down onto the stigma. [13]
H. africana can be harvested and used as food, medicine, and a good source of tannin. [8]
Rhizome extracts are used as an anti-dysenteric treatment in South Africa. [14]
Climate change can gravely affect sexual reproduction. Conservation efforts are not being made to rescue the H. africana. "...if pollinators disappear and might limit seed dispersal…In addition, they are being removed at a rapid rate for agricultural land expansion and overexploitation for medicinal use…". [15] With their[ who? ] extensive research, they have found that H. africana thrive in deeply moist environments surrounded by their pollinators. Since land is being destroyed and this organism is being exploited through its sale, their numbers will exponentially decline over time. "Our results show that the precipitation of the wettest month..was the most important variable contributing to the distribution of the two Hydnora species. This finding indicates that apart from the necessity of water for survival, ground moisture is an essential factor for most subterranean plants…adequate ground moisture levels are required for the relatively soft-tissued Hydnora flowers to break through the ground… which completes its entire life cycle below ground)." [15] As the climate gets warmer and warmer every year, H. africana loses its germination and goes extinct. Conservation efforts need to be made immediately in order to prevent its extinction. [15]
Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae. The term 'angiosperm' is derived from the Greek words ἀγγεῖον / angeion and σπέρμα / sperma ('seed'), meaning that the seeds are enclosed within a fruit. The group was formerly called Magnoliophyta.
Orchids are plants that belong to the family Orchidaceae, a diverse and widespread group of flowering plants with blooms that are often colourful and fragrant. Orchids are cosmopolitan plants that are found in almost every habitat on Earth except glaciers. The world's richest diversity of orchid genera and species is found in the tropics.
Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the corolla. Petals are usually surrounded by an outer whorl of modified leaves called sepals, that collectively form the calyx and lie just beneath the corolla. The calyx and the corolla together make up the perianth, the non-reproductive portion of a flower. When the petals and sepals of a flower are difficult to distinguish, they are collectively called tepals. Examples of plants in which the term tepal is appropriate include genera such as Aloe and Tulipa. Conversely, genera such as Rosa and Phaseolus have well-distinguished sepals and petals. When the undifferentiated tepals resemble petals, they are referred to as "petaloid", as in petaloid monocots, orders of monocots with brightly coloured tepals. Since they include Liliales, an alternative name is lilioid monocots.
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds. Pollinating agents can be animals such as insects, for example beetles or butterflies; birds, and bats; water; wind; and even plants themselves. Pollinating animals travel from plant to plant carrying pollen on their bodies in a vital interaction that allows the transfer of genetic material critical to the reproductive system of most flowering plants. When self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work.
Leucospermum commonly known as pincushions, is a genus of evergreen upright, sometimes creeping shrubs that is assigned to the Proteaceae, with currently 48 known species.
Entomophily or insect pollination is a form of pollination whereby pollen of plants, especially but not only of flowering plants, is distributed by insects. Flowers pollinated by insects typically advertise themselves with bright colours, sometimes with conspicuous patterns leading to rewards of pollen and nectar; they may also have an attractive scent which in some cases mimics insect pheromones. Insect pollinators such as bees have adaptations for their role, such as lapping or sucking mouthparts to take in nectar, and in some species also pollen baskets on their hind legs. This required the coevolution of insects and flowering plants in the development of pollination behaviour by the insects and pollination mechanisms by the flowers, benefiting both groups. Both the size and the density of a population are known to affect pollination and subsequent reproductive performance.
Zoophily, or zoogamy, is a form of pollination whereby pollen is transferred by animals, usually by invertebrates but in some cases vertebrates, particularly birds and bats, but also by other animals. Zoophilous species frequently have evolved mechanisms to make themselves more appealing to the particular type of pollinator, e.g. brightly colored or scented flowers, nectar, and appealing shapes and patterns. These plant-animal relationships are often mutually beneficial because of the food source provided in exchange for pollination.
Carrion flowers, also known as corpse flowers or stinking flowers, are mimetic flowers that emit an odor that smells like rotting flesh. Apart from the scent, carrion flowers often display additional characteristics that contribute to the mimesis of a decaying corpse. These include their specific coloration, the presence of setae, and orifice-like flower architecture. Carrion flowers attract mostly scavenging flies and beetles as pollinators. Some species may trap the insects temporarily to ensure the gathering and transfer of pollen.
Nectar is a viscous, sugar-rich liquid produced by plants in glands called nectaries, either within the flowers with which it attracts pollinating animals, or by extrafloral nectaries, which provide a nutrient source to animal mutualists, which in turn provide herbivore protection. Common nectar-consuming pollinators include mosquitoes, hoverflies, wasps, bees, butterflies and moths, hummingbirds, honeyeaters and bats. Nectar is an economically important substance as it is the sugar source for honey. It is also useful in agriculture and horticulture because the adult stages of some predatory insects feed on nectar. For example, a number of predacious or parasitoid wasps rely on nectar as a primary food source. In turn, these wasps then hunt agricultural pest insects as food for their young.
Eupomatia is a genus of three species of plants in the ancient family Eupomatiaceae, and is the sole genus in the family. Eupomatiaceae is recognised by most taxonomists and classified in the plant order Magnoliales. The three described species are shrubs or small trees, native to the rainforests and humid eucalypt forests of eastern Australia and New Guinea. The type species Eupomatia laurina was described in 1814 by Robert Brown.
Hydnoroideae is a subfamily of parasitic flowering plants in the order Piperales. Traditionally, and as recently as the APG III system it given family rank under the name Hydnoraceae. It is now submerged in the Aristolochiaceae. It contains two genera, Hydnora and Prosopanche:
A flower, also known as a bloom or blossom, is the reproductive structure found in flowering plants. Flowers consist of a combination of vegetative organs – sepals that enclose and protect the developing flower. Petals attract pollinators, and reproductive organs that produce gametophytes, which in flowering plants produce gametes. The male gametophytes, which produce sperm, are enclosed within pollen grains produced in the anthers. The female gametophytes are contained within the ovules produced in the ovary. In some plants, multiple flowers occur singly on a pedicel, and some are arranged in a group (inflorescence) on a peduncle.
The Proteaceae form a family of flowering plants predominantly distributed in the Southern Hemisphere. The family comprises 83 genera with about 1,660 known species. Australia and South Africa have the greatest concentrations of diversity. Together with the Platanaceae, Nelumbonaceae and in the recent APG IV system the Sabiaceae, they make up the order Proteales. Well-known Proteaceae genera include Protea, Banksia, Embothrium, Grevillea, Hakea, and Macadamia. Species such as the New South Wales waratah, king protea, and various species of Banksia, Grevillea, and Leucadendron are popular cut flowers. The nuts of Macadamia integrifolia are widely grown commercially and consumed, as are those of Gevuina avellana on a smaller scale.
Pollination syndromes are suites of flower traits that have evolved in response to natural selection imposed by different pollen vectors, which can be abiotic or biotic, such as birds, bees, flies, and so forth through a process called pollinator-mediated selection. These traits include flower shape, size, colour, odour, reward type and amount, nectar composition, timing of flowering, etc. For example, tubular red flowers with copious nectar often attract birds; foul smelling flowers attract carrion flies or beetles, etc.
Plant reproduction is the production of new offspring in plants, which can be accomplished by sexual or asexual reproduction. Sexual reproduction produces offspring by the fusion of gametes, resulting in offspring genetically different from either parent. Asexual reproduction produces new individuals without the fusion of gametes, resulting in clonal plants that are genetically identical to the parent plant and each other, unless mutations occur. In asexual reproduction, only single parent is involved.
This page provides a glossary of plant morphology. Botanists and other biologists who study plant morphology use a number of different terms to classify and identify plant organs and parts that can be observed using no more than a handheld magnifying lens. This page provides help in understanding the numerous other pages describing plants by their various taxa. The accompanying page—Plant morphology—provides an overview of the science of the external form of plants. There is also an alphabetical list: Glossary of botanical terms. In contrast, this page deals with botanical terms in a systematic manner, with some illustrations, and organized by plant anatomy and function in plant physiology.
Pouyannian mimicry is a form of mimicry in plants that deceives an insect into attempting to copulate with a flower. The flower mimics a potential female mate of a male insect, which then serves the plant as a pollinator. The mechanism is named after the French lawyer and amateur botanist Maurice-Alexandre Pouyanne. The resemblance that he noted is visual, but the key stimuli that deceive the pollinator are often chemical and tactile.
Anisomeles malabarica, more commonly known as the Malabar catmint, is a species of herbaceous shrub in the family Lamiaceae. It is native to tropical and subtropical regions of India, and Sri Lanka, but can also be found in Malaysia, Bangladesh, Myanmar, Bismarck Archipelago, Mauritius, Andaman Islands and Réunion.
Hydnora triceps is a holoparasitic flowering plant native to Africa that grows on the roots of Euphorbia dregeana. Completely lacking in chlorophyll, it depends on its host for water and nutrients. The plant structure is composed of only specialized stems, buds, and haustoria, lacking any leaf-like structures entirely. It spends its life underground and only emerges to flower.
Hydnora visseri, the Visser's hydnora, is a subterranean holoparasitic plant, lacking leaves and roots, and is described from southwestern Namibia and northwestern South Africa and has the longest tepal lobes of all Hydnora species. The genus Hydnora is composed entirely of holoparasitic plants that attach to the root of their hosts and are restricted to Africa and southwestern Asia.