18. Cyrillaceae Lindley
David E. Lemke
Shrubs or trees, evergreen or deciduous. Leaves usually borne towards ends of branches, alternate, simple; stipules absent; petiole present or absent; blade margins entire. Inflorescences terminal or axillary racemes, each flower in axil of caducous or persistent bract. Flowers bisexual; perianth and androecium hypogynous; sepals (4-)5(-8), connate at least proximally; petals (4-)5(-8), distinct; nectary disc present; stamens 5 or 10, outer (only) whorl antisepalous, distinct; pistils 1, 2-5-carpellate; ovary superior, 2-5-locular; placentation axile; ovules anatropous, unitegmic, tenuinucellate; styles 1, hollow; stigmas 2-5-lobed [unlobed]. Fruits berrylike or samaralike, dry, indehiscent. Seeds usually absent, sometimes 1 per locule, narrowly ovoid; seed coat absent; embryo straight; endosperm copious.
Genera 3, species 14 (2 genera, 2 species in the flora): e, sc United States, s Mexico, West Indies, Central America, n South America.
Members of Cyrillaceae are common shrubs or trees in moist, acidic habitats of the southeastern United States. On morphological, anatomical, and embryological grounds, Cyrillaceae have long been considered closely allied to Ericaceae (W. S. Judd and K. A. Kron 1993); molecular work confirms this placement (A. A. Anderberg et al. 2002). The fruits of some Cyrillaceae, including our species, are frequently devoid of seeds; reproduction is largely by root sprouts (J. L. Thomas 1961).
SELECTED REFERENCES Schneider, E. L. and S. Carlquist. 2003. Unusual pit membrane remnants in perforation plates of Cyrillaceae. J. Torrey Bot. Soc. 130: 225-230. Thomas, J. L. 1960. A monographic study of the Cyrillaceae. Contr. Gray Herb. 186: 1-114. Thomas, J. L. 1961. The genera of the Cyrillaceae and Clethraceae of the southeastern United States. J. Arnold Arbor. 42: 96-106. Zhang, X. P. and A. A. Anderberg. 2002. Pollen morphology in the ericoid clade of the order Ericales, with special emphasis on Cyrillaceae. Grana 41: 201-215.