Fake Mushroom Lures Pollinators into Floral Trap

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Fake Mushroom Lures Pollinators into Floral Trap

Two cast iron plants in captivity. Credit: Nino Barbieri Wikimedia (CC BY-SA 3.0) The cast iron plant, unusually for its kind, is named for its personality. As a houseplant and groundcover, it is virtually indestructible . It can get by on the barest of illumination, tolerates over- and under-watering, and has few pests. Its one drawback — that it is a sluggish grower — is probably an asset when grown outdoors, since that renders it non-invasive [See also: kudzu ]. As popular and commonly cultivated as it is, as a botanical specimen, it is somewhat unusual. In the wild, it exists on only a few small islands in the entire world. And for over 100 years, it was thought to be the world’s only flower pollinated by a slug. Yes, you read that right. A mollusk . It turns out that might not have been 100% accurate. Advertisement Some Japanese scientists decided to test this hypothesis by actually staking out some cast iron plants in their homeland in southern Japan. Because, as it turns out, no one had actually done that before throwing around their land-gastropod-pollination ideas. That hypothesis was formulated in 1889 by watching plants imported to Europe . And for another 100 years, no one else performed that most basic of natural history experiments: watch the organism in nature. It should be said that idea that a slug could pollinate its flowers was not quite as crazy as it seems. The genus to which the plant belongs, Aspidistra , is known for having a variety of oddball, unassuming flowers with a forest floor zip code. This suite of characteristics makes for some unusual pollinators, many of whom remain unknown. A typical flower has both male and female parts. The male parts are the stamens, which contain sacs of pollen called anthers, while the female part is the carpel, surmounted by the stigma, the surface upon which pollen must land in order to fertilize the flower. The flower of the cast iron plant. Credit: Suetsugu and Sueyoshi 2018 In the flower of a cast iron plant, the stamens are tucked under a fat stigma that nearly fills the floral cup. This configuration renders wind pollination or self-pollination impossible and means that only a very determined or very tiny pollinator can gain entry. It hints at something sinister – a trap . Cross section of cast iron flower. Note the exquisite sculpting of the stigma’s upper surface and the anthers tucked below. Credit: Suetsugu and Sueyoshi 2018 Like its kin, cast iron flowers grow partially buried in soil and covered by leaf litter (another reason wind pollination is out of the question). In captivity, they often make these flowers right in the pot they’re growing in, so if you own one, take a peek from time to time to see if your plant might be in cryptobloom. Advertisement For about 30 hours, the scientists surrounded and patiently watched wild cast iron flowers on Kuroshima Island , using red light […]