Ehleringer James
Department of Biology, University of Utah, 84112, Salt Lake City, UT, USA.
Oecologia. 1983 Mar;57(3):303-310. doi: 10.1007/BF00377172.
An individual Encelia farinosa (Asteraceae) from Death Valley, California is described that is completely lacking in the dense leaf pubescence covering characteristic of the species. While leaf absorptances to solar radiation of the mutant E. farinosa are much greater than those of the wild type, other morphological aspects and photosynthetic characteristics appear to be similar to those typical for E. farinosa. Leaf temperatures of mutant and wild type E. farinosa in the field are similar, but only because of steeper leaf angles and higher leaf conductances to water vapor in the mutant form. As a consequence of a greater water expenditure for transpirational cooling, the mutant E. farinosa becomes deciduous much earlier in the drought period than do the normal pubescent leaved E. farinosa.
描述了一株来自加利福尼亚州死亡谷的粉苞菊（菊科），它完全没有该物种特有的浓密叶片柔毛覆盖特征。虽然突变型粉苞菊叶片对太阳辐射的吸收率远高于野生型，但其他形态特征和光合特性似乎与粉苞菊的典型特征相似。在田间，突变型和野生型粉苞菊的叶片温度相似，但这只是因为突变型叶片角度更陡，对水蒸气的传导率更高。由于蒸腾冷却需要更多水分消耗，突变型粉苞菊在干旱期比正常有柔毛叶片的粉苞菊更早落叶。
