The families of flowering plants
Including Metabletaceae Dulac, Lewisieae (Lewisiaceae) Hook. & Arn., Montiaceae Dum., Spaetalumeae Wyeth & Nuttall, Talinaceae Doweld; excluding Hectorellaceae.
Habit and leaf form. Shrubs and herbs (commonly mucilaginous in leaves and stems). Normal plants. Plants succulent (often), or non-succulent. Helophytic to xerophytic. Leaves alternate, or opposite; when alternate, spiral; fleshy (often), or herbaceous; petiolate to sessile; non-sheathing; simple. Lamina entire; linear, or lanceolate, or oblanceolate, or ovate, or obovate; pinnately veined, or one-veined; cross-venulate. Leaves stipulate, or exstipulate (Claytonia). Stipules intrapetiolar; scaly (or sometimes, as in Portulaca, represented by axillary hairs). Lamina margins entire. Leaf development not graminaceous.
General anatomy. Plants with crystal sand (Calandrinia), or without crystal sand.
Leaf anatomy. The leaf lamina dorsiventral, or bifacial, or centric. Stomata present; on both surfaces (usually), or mainly confined to one surface; anomocytic, or paracytic. Hairs present (glandular and/or eglandular, diverse in form: see illustration). Adaxial hypodermis present (rarely), or absent. Lamina usually with mucilage cells. The mesophyll usually containing mucilage cells; usually containing crystals. The crystals raphides, or druses, or solitary-prismatic. Minor leaf veins without phloem transfer cells (Calandrina, Lewisia, Montia).
Axial (stem, wood) anatomy. Nodes unilacunar. Primary vascular tissues comprising a ring of bundles (usually), or in a cylinder, without separate bundles; at least usually collateral. Internal phloem dubiously present (e.g. in Montia), or absent. Medullary bundles absent. Secondary thickening absent, or developing from a conventional cambial ring. Primary medullary rays wide, or narrow.
The wood diffuse porous. The vessels small; solitary, or radially paired, or in radial multiples. The vessel end-walls simple. The vessels with spiral thickening, or without spiral thickening. The axial xylem without fibre tracheids; with libriform fibres. Included phloem absent.
Reproductive type, pollination. Unisexual flowers absent. Plants hermaphrodite. Pollination entomophilous.
Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in inflorescences; when aggregated, in cymes. The ultimate inflorescence units cymose. Inflorescences usually cymes, often dichasial or tending to cincinni. Flowers bracteolate (if the sepals are interpreted as bracteoles); small, or medium-sized; regular to somewhat irregular; cyclic; tetracyclic. Free hypanthium present to absent. Hypogynous disk present.
Perianth with distinct calyx and corolla, or sepaline (the latter if the ostensible calyx is interpreted as bracteoles, whereupon the corolla becomes a petaloid calyx); 7; 2–3 whorled; anisomerous. Calyx 2; 1–2 whorled; polysepalous, or gamosepalous (the members sometimes united basally); persistent; imbricate (the upper member overlapped). Corolla if not interpreted as calyx, (2–)5(–18); 1 whorled; polypetalous, or gamopetalous (sometimes basally connate). Corolla lobes markedly longer than the tube. Corolla imbricate; regular; white, or yellow, or pink, or purple (often satiny).
Androecium 5, or 10, or 4–100 (i.e. to many). Androecial members branched (bundled, when many), or unbranched; free of the perianth, or adnate (to the corolla base); free of one another, or coherent; when coherent 1 adelphous, or 2–7 adelphous (?); 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens. Stamens 3, or 4, or 5, or 10, or 6–50; isomerous with the perianth, or diplostemonous to polystemonous; when 5, alternisepalous (opposite the petals). Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Anther epidermis persistent. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral, or isobilateral. Anther wall initially with one middle layer; of the monocot type. Tapetum glandular. Pollen grains aperturate; 3–6 aperturate, or 13–