Description Platanaceae

example of p. orientalis



large, sympodial, deciduous tree, speckled bark sheds in large irregular sheets, leaving smooth surface mottled , pale, persistent bark @ base of trunk, indumentum large glandular hairs, multicellular , uniserrate or short uniserrate ramification (in candelabrum), in stellate fascicles; glandular hairs unicellular, globular capitulum, cuticular waxes without crystalloids, rods , plates
leaves variable shapes , nervation, simple, alternate, more or less distichous, isobilateral palmate 3 7 lobes (palmatifid palmatisect) whole edges or glandular teeth (each 1 midvein broadens towards glandular apex, ends in open hole), or penninerved , whole (platanus kerrii), shape common in young, vernal leaves in other species, vernation folded, petiole sheathed, enclosing axillary bud (bud free in p. kerrii), stipules foliose, large, intrapetiolar, tubular, caduceus, in p. kerrii scarious, small, basally fused petiole, domatia present, stomata irregularly anomocytic
stems aggregated rays in xylem, nodes septilacunar, cork cambium present , superficial, buds covered single scale
plants monoecious, flowers of each sex in separate inflorescences
inflorescences in large hanging peduncles, each 1 unisexual, globular capitulum, pedunculate or seated, numerous flowers, derived condensation of panicle, circular bract @ base , bracteoles among flowers
flowers small, inconspicuous, hypogynous, regular unisexual, receptacle short, smooth, hypogynous disk absent, perianth reduced, sepals number 3 four, eight, free or basally fused, shorter petals, triangular. petals number 3 four, eight, truncated-spatulate or vestigial, scarious, absent in female flowers, male flowers androecium haplostemonous, isostemonous, oppositisepal, number 3 four, eight, stamens, gynostemium short or vestigial, anthers basifixed, not versatile, dithecous, tetrasporangiate, elongated, connectivum apically widened, peltate, dehiscence along longitudinal valves; pistillidium present, female flowers superior gynoecium carpels apocarpous in 2 or 3 whorls, imperfectly closed apically, surrounded large petals, linear stylodious, stigmas internal, decurrent in 2 ridges, more or less dry, 2 ovules per carpel 1 aborts, orthotropous, bitegmic, crassinucellated, pendulous, apical marginal placentation, 3 or 4 staminodes 3-4, no nectaries
fruits in achene, clavate, grouped in globular capituliform infructescence, each fruit surrounded long hairs




























seeds small thin testa little endosperm, oily , proteinaceous, embryo thin , straight 2 linear cotyledons, uneven
pollen in subprolate monads, 16-22 μm in length, tricolpate, sextarugate, tectate-columellate, reticulated surface, base layer thick tectum
chromosomal number: 2n = 14, 16, 21, 42; x equal 7 or 8