It is
small and dense in the first case, with orange and often very darkly
colored petals, while it is loose and green in the meadows, with
yellower flowers. Numerous analogous cases might be given. On mountain
slopes in South Africa, and especially in Natal, a species of composite
is found, which has been introduced into culture and is used as a
hanging plant. It is called _Othonna crassifolia_ and has fleshy, nearly
cylindrical leaves, and exactly mimics some of the crassulaceous
species. On dry soil the leaves become shorter and thicker and assume a
reddish tinge, the stems remain short and woody and bear their leaves in
dense rosettes. On moist and rich garden-soil this aspect becomes [444]
changed at once, the stems grow longer and of a deeper green.
Intermediates occur, but notwithstanding this the two extremes
constitute clearly antagonistic types.
The flora of the deserts is known to exhibit a similar divergent type.
Or rather two types, one adapted to paucity of water, and the other to a
storage of fluid at one season in order to make use of it at other
times, as is the case with the cactuses. Limiting ourselves to the
alternate group, we observe a rich and dense branching, small and
compact leaves and extraordinarily long roots. Here the analogy with the
alpine varieties is manifest, and the dryness of the soil evidently
affects the plants in a similar way, as do the conditions of life in
alpine regions.
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