Phytologia (July 1998) 85(l):74-79. SEX MORPH DESCRIPTIONS OF MALOSMA LAURINA (ANACARDIACEAE), A POLYGAMOOIOECIOUS SPECIES Gary B. Perl mutter 151 North Lomita Avenue. Ojai, California 93023 U.S.A. ABSTRACT In 1994-1998 I examined laurel sumac {Malosma lawrina) shrubs in Matilija Canyon, Ventura County, California for sex-identifying characteristics, augmented by study of herbarium specimens. Malosma is confirmed as polygamodioecious with detailed descriptions of staminate, andromonoecious and pistillate sex morphs at the individual, inflorescence, flower and organ levels. Characteristics are presented for identifying sex morphs of individuals in the field. KEY WORDS: Malosma, Anacardiaceae, polygamodioecy INTRODUCTION Malosma laurina (Nutt. ex T. & G.) Nutt. ex Abrams (laurel sumac) is a large, evergreen shrub found commonly in coastal sage scrub and chapairal in southern and Baja California. Although it has been described as polygamous or polygamodioecious since its first published treatment (Torrey & Gray 1838; Brewer & Watson 1876; Abrams 1911; Barkley 1937; Wilken 1993), descriptions of unisexual and bisexual flowers or other sex-identifying characteristics of individual plants are largely lacking. The only distinctive description is of pistillate plants, from Engler (1883). The purpose of this study is to provide detailed descriptions of flower and inflorescence morphology, to verify the breeding system of M. laurina as polygamodioecious, and provide a tool for identifying sexes in the field. STUDY SITE Field studies were conducted in Matilija Canyon, just west of the junction of Matilija Creek and its Upper North Fork, in the eastern end of the Santa Ynez 74
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