|Abstract||Trees or shrubs, very rarely herbs or fleshy saprophytes. Leaves spiral, sometimes opposite or pseudowhorled, simple, entire, crenate or serrate, mostly evergreen and ± coriaceous (Malesia), exstipulate (stipule-like perulae of axillary buds occur in Diplycosia and Vaccinium p.p.). Flowers bisexual (rarely functionally unisexual; or the plant dioecious in extra-Mal.), characteristically regular, (4-)5 (rarely 6-7)-merous. Inflorescences terminal or axillary, entirely covered by perulae in bud, mostly in racemes, these sometimes arranged to panicles or condensed to umbels, or reduced to few-flowered fascicles, or even to a solitary flower. Sepals (reduced in Monotropastrum and Wirtgenia) very rarely free, generally connate below to a calyx tube, the latter free or ± adnate to the ovary, persistent, whether or not accrescent in fruit, lobes imbricate or open in bud. Corolla campanulate to funnel-shaped, urceolate or cylindric, sometimes slightly zygomorphous, caducous, lobed to various degree, lobes imbricate (sometimes ± contorted), rarely valvate in bud. Stamens usually 10 (rarely 5, 8, or up to 20), obdiplostemonous, rarely haplostemonous, inserted at the outer margin of the disk between its lobes, or slightly attached to the base of the corolla; filaments free (Malesia); anthers dorsifixed to almost basifixed, the 2 cells (thecae) not rarely extending into free or connate tubules, these muticous or sometimes (bi)aristate distally by the prolonged back-wall, opening by terminal or introrse, very rarely extrorse pores or slits, not rarely with projecting dorsal appendages or spurs; pollen in tetrads, simple in Monotropoideae. Gynoecium syncarpous, 5- or pseudo-10-, rarely 2-4- or 6-7-celled. Disk hypogynous or epigynous, often fleshy and nectariferous, entire or mostly 5-10-lobed. Ovary 1, superior, half-inferior or inferior, generally with as many cells as carpels; placentation central, with 1 or 2 lamellas per cell, each bearing mostly numerous, rarely 1, anatropous or obliquely amphitropous, 1-tegumented ovulus. Style 1; stigma obtuse, capitate or peltate, whether or not 5-7-lobed. Fruit a 5(-7)-valved, septicidal or (sometimes lately or irregularly) loculicidal capsule, which may be ± included by the accrescent, ± fleshy calyx, or a rather dry to fleshy berry (Malesia). Seeds usually numerous, small, whether or not winged or tailed at one or both ends; testa thin, often reticulate; embryo cylindric, small, with copious endosperm.|
Distribution. About 125 genera with approximately 3500 spp., predominantly woody, all over the world.