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ANATOMY OF KOEBERLINIA AND CANOTIA REVISITED
Arthur C. Gibson
Vol. 26, No. 1 (JANUARY 1979), pp. 1-12
Published by: California Botanical Society
Stable URL: http://www.jstor.org/stable/41424188
Page Count: 12
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Detailed anatomical descriptions of leaves and stems are presented for Koeberlinia and Canotia, desert perennials of North America with photosynthetic old stems. Koeberlinia has linear subulate leaves with conical unicellular trichomes, adaxial stornata, abundant palisade mesophyll, and relatively few tannin cells; whereas Canotia has deltoid scales lacking trichomes and having abaxial stornata, undifferentiated mesophyll, and abundant tannin cells. Stem anatomy of these genera is also dissimilar even though both have adaptations to facilitate stem photosynthesis. Myrosin cells are present in inner cortex of Koeberlinia. Woods are superficially similar in vessel and fiber dimensions; however, Canotia has low, narrow rays with abundant resin and prismatic crystals, whereas Koeberlinia has higher, wider rays lacking resin and crystals, and its vessels appear to have vestured pits. Bark anatomy of these genera is fundamentally different. A previous report of secretory ducts in Koeberlinia is incorrect. Those features shared are judged to be convergent, and the differences are great enough to negate their classification together in the bigeneric Koeberliniaceae. A recommendation is made to reassign Canotia to Celastraceae and Koeberlinia to or near Capparaceae.
Madroño © 1979 California Botanical Society