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Floral anatomy of the Styracaceae, including observations on intra-ovarian trichomes

Authors :
William C. Dickison
Source :
Botanical Journal of the Linnean Society. 112:223-255
Publication Year :
1993
Publisher :
Oxford University Press (OUP), 1993.

Abstract

All eleven genera of the Styracaceae were examined with respect to floral morphology and anatomy. Floral structure and vascularization are described in detail. Flowers of the family exhibit different degrees and patterns of specialization. All Styracaceae show some degree of basal non-divergence of perianth members, forming a hypanthium that is adnate to the ovary wall to a lesser or greater extent. The extent of reduction and amplification in the number of sepals, petals, stamens, and carpels varies widely among genera, and generally the non-divergence, decrease, or increase in parts is not equally pronounced in the different whorls of the same sower. Genera cannot be readily aligned in an intergrading sequence of morphological advancement. Stamen form and anatomy is variable. A fibrous endothecium ranges from well-developed to weakly formed or absent. A nearly uniform feature of the styracaceous gynoccium is the presence of incompletely septate ovaries. The major points of variation in the floral vascular system relate to the number, mode of origin, and degree of independence of sepallary traces; degree of independence of the androecial vasculature; the level at which the common petal and petaladstamen or sepal and sepalad-stamen bundles separate to their component parts; organization of the ventral ovarian supply; and the occurrence of ventral bundles in the style. Floral vascularization provides evidence that the family was derived from an obdiplostemonous ancestor. A unitegmic ovule is predominant in the family and starch is present in the megagametophyte of some taxa. An unusual feature of the flowers of the Styracaceae is the occurrence of stellate and lignified intraovarian trichomes. Numerous similarities in floral morphology and anatomy between Styracaceae and Ericales are pointed out.

Details

ISSN :
00244074
Volume :
112
Database :
OpenAIRE
Journal :
Botanical Journal of the Linnean Society
Accession number :
edsair.doi...........a5c1be2524fb9a9abfd95c1dba481294
Full Text :
https://doi.org/10.1111/j.1095-8339.1993.tb00318.x