Beauty may be in the eye of the beholder, but a newly discovered orchid is not the best choice for many as the centerpiece of a corsage.
Gastrodia agnicellus, from the forests of Madagascar, has been awarded the world’s ugliest orchid label by botanists at the Royal Botanic Gardens, Kew in the UK.
And yet the plant is fascinating, unusual among orchids, and an indication of how much we may be missing from what is hiding in the undergrowth of the forest.
This, in turn, highlights the importance of protecting the environment: although it has only just been discovered, G. agnicellus is already considered an endangered species.
It seems reasonable that the plant was not recognized until September last year. G. agnicellus spends most of its life underground, only emerging in August and September to bloom and fruit under the leaf humus on the forest floor before disappearing underground again.
Those flowers are also small – only 11 millimeters long (0.43 in) – and inconspicuous against the debris on the ground, ranging from brown to white in color. Yet the flower had already been found; it’s just no one realized the meaning until recently.
Blooming G. agnicellus, after leaf litter was cleared. (J. Hermans, Curtis’s Bot. Mag., 2020)
“Material of the new Gastrodia agnicellus, found near Ifanadiana in southeastern Madagascar in the 1990s, was recognized as belonging to the genus and was initially considered G. madagascariensis‘wrote botanist Johan Hermans of Kew Gardens in the official description of the species.
“During an excursion to Madagascar in December 2017, a Gastrodia with high, dry infructescences was first noticed in the Ranomafana area. On a more recent trip, in September 2019, the same site was revisited and after extensive search, a few new developing fruit-bearing inflorescences were found.
“It was only when a layer of leaf litter was lifted that a small number of flowers were also discovered. It soon became clear that the flowers were very different from those of the newly validated G. madagascariensis and that it was an unrecognized species. “
The orchids were found in deep shade in a moist evergreen forest, at the base of trees, hidden among flowers, moss and leaf litter. Still, they gave off a pleasant, musky, rose-like scent, Hermans wrote, which grew stronger with warmer temperatures.
After the flowers are pollinated, the stem elongates, which likely promotes seed dispersal.
The fully developed fruits. (J. Hermans, Curtis’s Bot. Mag., 2020)
And, as with other members of the Gastrodia genus, the orchid plant has no leaves – in fact, it has no photosynthetic tissue at all.
That’s because this plant is a holomycotroph – a type of orchid that relies solely on a relationship with fungus for the nutrients it needs to survive. The fungus takes nutrients such as carbon from the soil or other plants, and the orchid gulps down what it needs from the fungus.
All orchids rely on such a relationship with fungus at some point in their life cycle, but as most species mature, their dependence on fungus fades. It is not clear exactly what the fungus gets out of the relationship, but in many cases it is part of a mycorrhizal network, where the fungus exchanges nutrients with other plants.
In front of G. agnicellusThe exact relationship with fungus is one of many unknowns, but it will be important to find out. Its habitat under specific trees suggests that the mycorrhizal system it relies on is quite specific. This is consistent with other species in the genus, but it also means that threats to its habitat, such as encroaching human agriculture and wildfires, can be a serious problem.
It is also unclear how the plant is pollinated. Ants were observed crawling in and out of the flowers – probably, Hermans remarked, to steal nectar – so that’s a possible pollination route. But more research will need to be done to determine how G. agnicellus relies on and contributes to the complex ecosystem it inhabits.
There is good news, however. Although the range of the plant appears small, it has been found in the protected area of Ranomafana National Park. Which, according to Kew Gardens, means it has some measure of protection against anthropogenic habitat loss for now.
G. agnicellus has been selected as one of the top 10 new varieties of 2020 at Kew Gardens and described in Curtis’ Botanical Magazine.