The families of flowering plants
~ Hamamelidaceae (Altingioideae, Liquidambaroideae)
Including Balsamaceae Lindl., Liqidambaraceae Pfeiff.
Habit and leaf form. Trees (sometimes very large); resinous (ducts in axes and leaves). Leaves alternate; non-sheathing; simple. Lamina dissected; palmatifid (or tricuspidate); pinnately veined, or palmately veined; cross-venulate. Leaves stipulate. Stipules intrapetiolar; caducous (small). Lamina margins entire (rarely), or serrate, or dentate. Domatia occurring in the family (recorded in Liquidambar); manifested as pockets, or hair tufts.
Leaf anatomy. Stomata paracytic. Adaxial hypodermis present. Lamina with secretory cavities. Secretory cavities schizogenous.
Axial (stem, wood) anatomy. Secretory cavities present (in the pith). Cork cambium present; initially superficial. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring.
The vessels without vestured pits. The parenchyma apotracheal (scarce). Included phloem absent.
Reproductive type, pollination. Plants monoecious (the male flower consisting of a globose stamen-cluster, enclosed in a bract). Gynoecium of male flowers absent.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences. Inflorescences in terminal racemes (male), or in globular heads cf. Platanus (female).
Perianth sepaline, or vestigial; 0 (male flowers), or 12–50 (i.e. many, of minute lobes or scales, in female flowers); more or less accrescent (in female flowers).
Androecium 12–100 (i.e. many the male inflorescences consisting terminal racemes of globose stamen-clusters); exclusively of fertile stamens. Stamens 12–50. Anthers basifixed; dehiscing via longitudinal slits (?), or dehiscing by longitudinal valves; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Tapetum glandular. Pollen grains aperturate; polyaperturate; foraminate; 2-celled.
Gynoecium 2 carpelled. The pistil 2 celled. Gynoecium syncarpous; synstylovarious; inferior. Ovary 2 locular. Stigmas 2; dry type; papillate; Group II type. Ovules 20–50 per locule; horizontal; anatropous; bitegmic; crassinucellate. Embryo-sac development Polygonum-type. Antipodal cells formed; 3; not proliferating; very ephemeral. Endosperm formation nuclear.
Fruit non-fleshy; dehiscent; a capsule. Capsules septicidal. Gynoecia of adjoining flowers combining to form a multiple fruit. The multiple fruits coalescing, or not coalescing (?). Dispersal unit the inflorescence (this globular, hard, dry, of many capsules). Cotyledons 2; flat. Embryo straight.
Seedling. Germination phanerocotylar (Liquidambar).
Physiology, phytochemistry. Sugars transported as oligosaccharides + sucrose (Liquidambar). Not cyanogenic. Arbutin absent. Iridoids detected (Liquidambar); Route I type (?). Proanthocyanidins present; cyanidin and delphinidin. Flavonols present; quercetin and myricetin. Ellagic acid present.
Geography, cytology. Temperate to tropical. Asia Minor, temperate and tropical Southeast Asia, North and Central America. X = 8.
Taxonomy. Subclass Dicotyledonae; Crassinucelli. Dahlgrens Superorder Rosiflorae; Hamamelidales. Cronquists Subclass Hamamelidae; Hamamelidales. APG 3 core angiosperms; core eudicot; unplaced at Superordinal level; Order Saxifragales.
Species 10. Genera 3; Altingia, Liquidambar, Semiliquidambar.
Economic uses, etc. Sources of timber.
Illustrations. • Technical details: Liquidambar. • Altingia gracilipes: Hook. Ic. Pl. 29 (1909).
The descriptions are offered for casual browsing only. We strongly advise against extracting comparative information from them. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG).
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 16th May 2016. delta-intkey.com’.