The families of flowering plants
Excluding Quintiniaceae, Sphenostemonaceae.
Habit and leaf form. Small to medium sized trees. Leaves (sub-) whorled; leathery; petiolate; simple. Lamina entire; pinnately veined; cross-venulate; attenuate at the base. Leaves exstipulate. Lamina margins finely serrate. Vegetative buds scaly.
Leaf anatomy. The leaf lamina dorsiventral. Stomata present; mainly confined to one surface (abaxial); anomocytic. Hairs present; unicellular. Unicellular hairs simple. Adaxial hypodermis absent. The mesophyll with sclerenchymatous idioblasts (thin walled brachysclereids); containing crystals (as scattered styloids).
Axial (stem, wood) anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar. Primary vascular tissues in a cylinder, without separate bundles. Secondary thickening developing from a conventional cambial ring. Primary medullary rays narrow.
The vessel end-walls very oblique; scalariform (with very numerous cross-bars). The axial xylem with tracheids; with fibre tracheids. The parenchyma scanty paratracheal, or apotracheal.
Reproductive type, pollination. Plants hermaphrodite, or andromonoecious.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in inflorescences; in panicles. Inflorescences terminal; rusty-pubescent panicles comprising compound spikes of sessile flowers. Flowers cyclic.
Perianth of tepals; 4; free; 2 whorled (as here interpreted, consisting of four decussate, caducous tepals, the outermost one the largest and more or less enclosing the other three); deciduous.
Androecium 8(–11). Androecial members free of the perianth; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens 8(–11); triplostemonous; filantherous (the filaments somewhat laminar-expanded in male flowers, filiform in hermaphrodite flowers, sometimes accrescent). Anthers basifixed (oblong); dehiscing via longitudinal slits; tetrasporangiate. Endothecium developing fibrous thickenings. Pollen shed as single grains. Pollen grains aperturate; 3 aperturate; colporate.
Gynoecium 8–15 carpelled. Carpels increased in number relative to the perianth. The pistil 8–15 celled. Gynoecium syncarpous; synovarious (the carpels laterally connate, ventrally adnate to the solid core of central tissue); superior. Ovary 8–15 locular. Gynoecium non-stylate (the distinct stigmas sessile). Stigmas 8–12 (conduplicately folded). Placentation axile. Ovules 4 per locule; superposed (in a single row on the placenta); non-arillate; anatropous; unitegmic; crassinucellate. Endosperm formation cellular.
Fruit non-fleshy; dehiscent and a schizocarp. Mericarps viewed as a schizocarp, 8–15; comprising follicles. Fruit viewed as syncarpous, a capsule (the mature carpels separating from the central column except at the top, spreading out from the base and dehiscing ventrally). Capsules initially septicidal (prior to the ventral opening of the carpels). Seeds copiously endospermic; small; winged. Embryo well differentiated. Cotyledons 2 (these shorter than the radicle). Embryo straight.
Geography, cytology. Paleotropical. Tropical. New Caledonia.
Taxonomy. Subclass Dicotyledonae; Crassinucelli, or Tenuinucelli (? ovules crassinucellate but unitegmic, endosperm formation cellular). Dahlgrens Superorder Corniflorae; Cornales. Cronquists Subclass Dilleniidae; Theales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; campanulid; Order Paracryphiales.
Species 2. Genera 1; only genus, Paracryphia.
General remarks. See Dickison and Baas 1977. The comparative descriptive data compiled here show Paracryphia differing from Sphenostemon) (q.v.) in at least ten conspicuous characters representing vegetative, floral and fruit morphology, in addition to the winged seeds (and non-ruminate endosperm?). Quintinia, also referred to Paracryphiaceae by APG III in 2009, appears to bear so little morphological resemblance to Paracryphia that, pending further investigation or pursuit of the literature, it is retained here in Saxifragaceae.
Illustrations. • Paracryphia alticola, as P. suaveolens: Baker, J. Linn. Soc. Bot. 45 (1922). • Quintinia serrata, for comparison: Hook. Ic. Pl. 5–6 (1842).
We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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). See also Guidelines for using data taken from Web publications.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 24th October 2017. delta-intkey.com/angio’.