And yet we do have some experience with situations where scarcity is nonexistent.
Ha-lophytes.These are plants living in situations where the substratum contains a high proportion of sodium chloride.
With regard to the occurrence of plants, such as Juncus effusus, which possess xerophytic characters and yet live in situations which are not ordinarily of marked physiological dryness, it should be remembered that such habitats are liable to occasional physical drought; and a plant must eventually succumb if it is not adapted to the extreme conditions of its habitat.
The xerophytic characters being present, it is not surprising that many marsh plants, like Juncus effusus and Iris pseudacorus, are able to survive in dry situations, such as banks and even garden rockeries.
In the daytime "the gorged females rest motionless on the walls and ceilings of rooms, choosing always the darkest situations for this purpose" (Austen).