Range + variation in angiosperms etc 1. woody + herbaceous - 2. differing in length of life - 3. plasticity of structures of plants - a. Ranunculus - water crowfoot, b. 1. produces dissected leaves water - leaves above water whole b. Dandelion - Bonnier grew parts of same plant at low alt + at alpine station. Both grew but large at low alt. & small at high. Ability of plant to become adjusted to differing conditions. c. Genetic variation - not plastic d. mutation or sport sometimes extends range of plants - Each species or variety is compelled to live within a certain range of condition within this range the optimum combination may be found. The farther away from the optimum combination the more the plant must be protected. This optimum is an interaction of several to many factors - moisture - temp. soil conditions etc. an inherited tendency allows plant to vary within limits.