To the wandering bird, bee, or insect, a flower is both a billboard and a wayfinding sign—its colors and patterning have evolved to attract pollinators and direct them towards the plant's pollen and nectar. There's one prerequisite: the visual cues require a diurnal pollinator to find the flower. What about bats, then? How do nocturnal, echolocating pollinators navigate a floral terrain? According to an article in Science, they may use acoustics.
In South Africa's coastal grasslands, to explore a forest is to walk along its canopy—indeed, it's the only way to observe an extraordinary group of so-called underground trees, where only the uppermost leaves and branches are visible. The rest of the tree is submerged below the deep sandy soil, creating a clonal network of underground "forests." By all appearances, the forests are merely low shrubs, which presents the philosophical riddle: if a tree falls and no one can see the forest, what of the forest?