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The families of flowering plants.                                                                                                                                                                

Paracryphiaceae Airy Shaw.

                        

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IncludingQuintiniaceaeExcluding 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. Stomata present; mainly confined to one surface (abaxial); anomocytic. Hairs present; unicellular. Unicellular hairs unbranched.

Adaxial hypodermis absent. Lamina dorsiventral. The mesophyll with sclerencymatous idioblasts (thin walled brachysclereids); containing calcium oxalate crystals (as scattered styloids).

Stem anatomy. Cork cambium present; initially superficial. Nodes tri-lacunar. Primary vascular tissue in a cylinder, without separate bundles. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids; with fibre tracheids; with vessels. Vessel end-walls very oblique; scalariform (with very numerous cross-bars). Primary medullary rays narrow. Wood 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 of sessile flowers (compound spikes). Flowers cyclic.

Perianthof ‘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). Dahlgren’s Superorder Corniflorae; Cornales. Cronquist’s 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. Paracryphia exemplifies the well known difficulties in distributing certain Dicot families between Dahlgren’s Araliiflorae and Corniflorae. It is equally hard to assign them with confidence to the higher level groupings Crassinucelli and Tenuinucelli. This is interesting, given that the latter evidently represent a major divergence in the Dicot line of descent (cf.Young and Watson 1970, Chase et al. 1993). Relatively recent inclusion here of Quintinia (Quintiniaceae) has not yet been accounted for in this desciption.

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