Anatomy of Photosynthetic Old Stems of Nonsucculent Dicotyledons from North American Deserts

Publisher Website
Google Scholar
Abstract
Stem anatomy is analyzed for 30 native species of nonsucculent desert and semidesert perennials from North America. Observations on anatomical convergence of green-stemmed perennials from around the world are once again confirmed. Typical species have well-developed cuticle, sunken stomates, delayed formation of periderm, thick chlorenchyma, and much sclerenchyma in either the cortex of phloem or both. Four basis designs are recognized, based on the positions of supportive tissues versus chlorenchyma, and the origins of these types are discussed. Each repetitious anatomical feature is analyzed by considering various physiological problems of living in deserts. Crude calculations on stomatal and superstomatal resistances of pores reveal that the importance of sinking of stomates may not always have been in saving water, and some alternative hypotheses are suggested.

This publication has 0 references indexed in Scilit: