Legend has it that I am a carnivorous plant.
In fact, the truth is often surprising.
I am Hydnora africana, from arid and semi-arid regions of Africa, from southern Angola, along the Cape coast, around eastern Cape and southern KwaZulu-Natal, all of which have my turf.
Distribution of Hydnora in Africa and the Arabian Peninsula / Elijah, M.M. et al.2021
My Chinese name should be African Egret Flower, although I don't know why Chinese gave me such a name. But according to the literal translation, I think I can also call it African fungus.
Why is it called a fungus flower? Because when people found me, they only saw a red ball of flowers (which turned out to be my flowers), as if they had suddenly popped out of the soil. At that time, people thought that I might be some kind of fungus, because fungi like to appear suddenly after a rainy day, and there is no chlorophyll in the whole body, such as those mushrooms, red umbrellas, white poles, and don't they also appear in this way?
African Hydnora
However, botanists eventually confirmed that I was not a fungus, but a real angiosperm. So, the botanists gave me the genus name Hydnora, which means "fungus-like." And because I appear in Africa, the species plus word after the genus name uses africa, which means "African". The genus name Hydnora + species plus word africa is my scientific name. My name is called differently in different countries, and the same place may be called differently, so no matter what name people are used to calling me, if you want to prove that they are indeed speaking, please identify my Latin name Hydnora africana, the only scientific name certified by international standards.
Previously I belonged to the large family of Hydnoraea, but now the mycophyllaceae have been abolished, and all the genera of hydnora (i.e., my genus) under the mycophageae family have been classified together with the genus Prosopanche into the Aristolochiaceae family, and we are the only two genera of angiosperms that have no leaf structure at all, not even scales.
My host plant
Some people are curious, how did I suddenly jump out of the soil? Is there any special skill like the Qi Tian Dasheng in Chinese mythology?
You're right, I just have a special skill, and that's "parasitism."
In biological terminology, "parasitism" refers to "two organisms living together, one benefiting and the other suffering, the latter providing nutrients and a place to live for the former, and the relationship between this organism is called parasitism." In layman's terms, it is to occupy other people's bodies and steal other people's nutrients. The parasitic relationship between animals is no stranger to everyone, because you humans sometimes have parasites in your body.
We also have parasitic relationships between our plants. For example, I am a whole parasitic plant, I don't produce nutrients myself, I rely on stealing it all. Because I don't have chlorophyll myself and can't photosynthesis, I have to steal nutrients from my host, Euphorbia, for me to grow.
At present, I have found that there are about 10 species of hosts, all of which are Euphorbia species, and one of the more famous hosts is Euphorbia caput-medusae. Speaking of Medusa, you must not forget this beautiful woman in Greek mythology, who was enchanted by Athena and her hair became a monster with many snakes. My host, Euphorbia Medusa, has many branches on the main stem side, really like the mythical Medusa, which is amazing.
Hydnora africana and Euphorbia caput-medusae
My name "caput-medusae" means "Medusa's Head" in Latin. Euphorbia Medusa originates in Cape Town, South Africa, and has become a relatively high-end succulent because it is uncommon in China.
Euphorbia Medusa
How did I steal euphorbia from Medusa? I confessed.
The complete me is composed of a vegetative structure and a reproductive structure, my vegetative structure lives completely underground, and is highly degenerate, the characteristics are very inconspicuous, it is impossible to distinguish between the stem, the root and the leaf part, it does look very much like the root organ, but there is no root structure and tissue, so I call it rhizome for the time being.
Rhizome of Hydnora Africana / Williams V. L. et al., 2011
The rhizomes of our floral family have many wart-like protrusions on the surface. The protrusions on the surface of my rhizomes are more regular, arranged to form 5-6 ridges. Our rhizomes are generally brick-red or red-pink when they are alive, hard, fleshy, and can ooze viscous red body fluids; when dry, they are dark brown and lignified.
The rhizome of Hydnora africana and the roots of its host
Once our host's roots are detected, we secrete an enzyme that dissolves the hard tissue of the host's roots in order to adsorb ourselves into it, a process done by our sucker, which once connected to the host's roots, we are able to live on the nutrients provided by the host and quickly develop an underground rhizome that is much larger than the host's root, from which buds are produced and eventually exposed to the ground.
Am I a carnivorous plant? This is not the truth
People used to think I was an insectivore, and even painted me with an exaggerated image of a mouth full of teeth. Actually, that's not true, it's your own horror movies that you've watched too much and imagined it, you humans are really interesting.
I did imprison some insects, but I wasn't trying to eat them, I just wanted them to give me a leg and do the task of passing on the generations for me. As for why I shut them up, it starts with my reproductive structure.
Hydnora africana (the thin root in the lower right corner is the root of the host)
I have dormant buds on my rhizomes that develop under the right conditions to form buds, and after a year or so of gestation, especially after a rain, the ripe buds break through the soil and the flowers open on the ground.
The structure of the flowers is also very simple, most of them are exposed to the ground, and some of them are still hidden in the soil. There are flower quilts exposed on the ground, or some flower tubes. My flowers are usually 3 lobes, but the flowers are still born together by the lobes tip, forming an elliptical spherical shape that you see from the outside.
From the inside, my flowers look like a house, with two rooms, the upper room is called the stamen room, and the lower room is called the pistil room. The 3 pieces of anthers of the stamens are connected to each other to form an anther ring, like the floor of the stamens chamber, separating the two rooms, leaving an orifice in the center, which becomes a passage for pollen and visitors to travel between the two rooms.
Hydnora africana flowers are sliced together in longitudinal sections
The stigma is also 3 petals, forming a cushion-like structure at the base of the lower pistil chamber, and the stigma surface remains wet and sticky throughout the flowering period. Further down the pistil chamber is the location of the ovary, which will develop into fruit in the future.
When I first bloomed, 10 meters away you could smell a pungent smell similar to carrion, and this disgusting smell was emitted by a structure called osmophore inside the flower sheet, which sunk into the inner surface of the flower cover, not only looking like a spongy pudding on the outside, but also smelling of pudding.
Osmophore structure on Hydnora africana flower quilt (white part)
Because the osmophores are white, botanists call them "white bodies," while some botanists like to call them "whitet bodies." It was detected that the smell of carrion emitted by osmophore contained dimethyl disulfide and dimethyl trisulfide, both compounds that were also detected in the "corpse flower" Helicodiceros muscivorus of the family Tiannanxing.
When the flowers first bloom, the inner surface of the flower is orange-red and the osmophore is white; after a few hours, the flower is darkened by the orange-red color of the inner surface, while the osmophore turns gray.
With such an eye-catching flower and such a unique taste, I naturally succeeded in attracting a group of "smelly" flower visitors.
Many Coleoptera insects, especially beetles, are attracted to my smell. They settle on the trespass, then enter the flower through the gap between the trichomes in the middle of the flower cover, and climb to the osmophore structure, the source of the odor, and they fall into the flower chamber. The smooth inner surface and steep tilt of the stamen chamber prevented them from escaping, and they passed through the central hole of the anther ring and entered the lower pistil chamber, but the anther ring closed and trapped them in the coming pistil chamber. And so I imprisoned them.
Anthers from Hydnora africana
Beetles visit flowers
After a few hours, some take more than a day for the anthers to crack and release pollen. At this time, the inner wall tissue of the stamen chamber is dotted and darkened, and the surface appears textured and no longer smooth. The trapped beetles can finally escape, but they have been coated with a sticky pollen coat.
A: Flower longitudinal section, ruler = 1 cm; B: Visiting insects and anther rings; C: Pollen on the hair of visiting beetles, ruler = 20um. ;D: The beetle is covered in pollen
When the pollen was released, my task of passing on the generations was basically completed, and the smell of carrion began to disappear. Generally this strong odor can last for 2-5 days.
About 1-2 years after the flowering period, my fruit is ripe, and my fruit is 7–12 cm in diameter. The fruits and rhizomes of our genus Flora grow all underground, but my relative H. Abyssinica has been found to have its fruit exposed to the ground, and its fruit ripens quickly, generally only about 5 months.
Hydnora abyssinica dew on the ground / Williams V. L. et al., 2011
Other members of the genus Floral
I have 7 other siblings in the genus, they look similar to me, but there are some differences, show you their strange looks (one is absent).
(a) Hydnora arabica (b) H. visseri (c) H. abyssinica (d) H. esculenta (e) H. africana (f) H. triceps (g) H. johannis
We don't have many hosts in the genus Euphorbiaceae, Beans (Fabaceae) and Burseraceae, and we start to settle on their roots and grow with them.
We are used in African folklore to treat diarrhea, dysentery, kidney and bladder diseases and other diseases, and we are sometimes seen in African markets, where some traders go to look for us and then sell them as medicinal herbs in the market.
Although our flowers taste disgusting, our fruits are not only not poisonous, but also delicious. Some animals including jackals, baboons, rhinos, elephants, porcupines and small mammals love to come to us for a good meal. Of course, you humans at the top of the food chain are also hungry, have also eaten our fruit, and said that our fruit tastes delicious, even a little strawberry milk. But our seeds are hard to digest so we can make a long-range trip as the animals move around and excrete.
At present, you humans have discovered our 8 kinds of fungal flowers, I think I should have other brothers and sisters, this needs you to continue to explore, maybe it will not be long before my ninth and tenth siblings will be discovered.
Hydnora arabica / JAY F.B. 等,2018
The Fruit of Hydnora Tricepsd / Maass E. & Musselman L. J., 2004
Hydnora abyssinica / Photo by Ottmar Kullmer
bibliography:
[1] Thorogood C . Hydnora : The strangest plant in the world? [J]. Plants People Planet, 2019, 1(1):5-7.
[2] Bolin J F , Maass E , Musselman L J . Pollination Biology of Hydnora africana Thunb. (Hydnoraceae) in Namibia: BroodSite Mimicry with Insect Imprisonment[J]. International Journal of Plant Sciences, 2009, 170(2):157-163.
[3] African Hydnora