Including Plumeriaceae Horan., Emetiaceae Dulac
Excluding Asclepiadaceae, Periplocaceae, Plocospermataceae
Habit and leaf form. Trees (a few, e.g. in Tabernaemontana, Dyera), or shrubs, or lianas (mostly), or herbs (e.g. Vinca); laticiferous. Climbing (usually), or self supporting (sometimes); mostly stem twiners (with hooks). Leaves evergreen; alternate, or opposite, or whorled; when whorled 3 per whorl; simple. Lamina entire; pinnately veined. Leaves stipulate (rarely), or exstipulate. Stipules when present, interpetiolar (small). Domatia recorded (in 15 genera); represented by pits, or pockets, or hair tufts.
General anatomy. Plants with laticifers (non-articulated, branched or unbranched). The laticifers in leaves and in stems.
Leaf anatomy. Epidermis with crystal idioblasts (sometimes), or without crystal idioblasts. Stomata anomocytic, or paracytic.
Lamina dorsiventral (usually), or isobilateral (rarely); with secretory cavities, or without secretory cavities (?). The mesophyll with sclerencymatous idioblasts (`spicular cells'), or without sclerenchymatous idioblasts. Minor leaf veins without phloem transfer cells (Dipladenia, Trachelospermum, Vinca).
Stem anatomy. Secretory cavities present, or absent (?). Cork cambium present; initially deep-seated (rarely), or superficial. Nodes unilacunar. Primary vascular tissue bicollateral. Internal phloem usually present. Secondary thickening developing from a conventional cambial ring, or anomalous; from a single cambial ring. `Included' phloem present (Lyonsia), or absent. Xylem with tracheids; with fibre tracheids, or without fibre tracheids; with vessels. Vessel end-walls simple, or scalariform (with few bars). Vessels with vestured pits. Wood parenchyma apotracheal (usually), or paratracheal (in a few genera). Sieve-tube plastids S-type.
Reproductive type, pollination. Hermaphrodite. Pollination mechanism conspicuously specialized (usually with a highly modified stylar head and specialised anthers).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'. The terminal inflorescence unit usually a panicle. Flowers bracteate; bracteolate; regular; usually 4-5 merous; cyclic; tetracyclic. Hypogynous disk usually present.
Perianth with distinct calyx and corolla; 10; 2 whorled; isomerous. Calyx 5; 1 whorled; gamosepalous; regular; imbricate (quincuncial); with the odd member posterior. Corolla 5; 1 whorled; appendiculate (often, in the form of scales in the throat); gamopetalous; contorted (usually), or valvate (rarely); funnel-shaped, or hypocrateriform; regular; white, or yellow, or red, or pink, or purple, or blue.
Androecium 5. Androecial members adnate (epipetalous); united with the gynoecium, or free of the gynoecium; free of one another, or coherent; 1 - whorled. Androecium exclusively of fertile stamens. Stamens 5; isomerous with the perianth; oppositisepalous. Anthers cohering, or connivent (often sagittate, empty below and prolonged into spines, sometimes united with the stylar head), or separate from one another; adnate; tetrasporangiate; appendaged (by prolongation of the connective), or unappendaged. Microsporogenesis successive, or simultaneous. The initial microspore tetrads tetrahedral, or isobilateral, or decussate. Anther wall initially with one middle layer, or initially with more than one middle layer. Tapetum glandular. Pollen grains aperturate; (2-)3-4 - aperturate; porate, or colporate; 2-celled, or 3-celled.
Gynoecium 2; syncarpous (but sometimes the carpels united only by their styles); synstylovarious to eu-syncarpous, or synstylous (with a ring of hairs beneath the stigma); superior, or partly inferior. Ovary 1-2 locular. Gynoecium transverse. Styles 1. Stigmas 1 (the head usually massively thickened, contracted in the middle, with a ring, a ring of hairs or a membrane below); wet type, or dry type; papillate, or non-papillate; Group II type, Group III type, and Group IV type. Placentation apical. Ovules 2 per locule, or 4 per locule, or 6 per locule, or 25-50 per locule (`many'); pendulous; anatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed; 3; not proliferating; ephemeral. Synergids pear-shaped. Endosperm formation nuclear. Embryogeny caryophyllad.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent, or a schizocarp; when schizocarpic comprising follicles, or comprising mericarps; a capsule, or a berry. Seeds copiously to scantily endospermic, or non-endospermic. Endosperm oily. Seeds usually flat; conspicuously hairy (comose, in the Apocynoideae), or not conspicuously hairy (Plumerioideae). Cotyledons 2. Embryo achlorophyllous (10/12); straight.
Seedling. Germination phanerocotylar, or cryptocotylar.
Physiology, biochemistry. Cyanogenic (rarely), or not cyanogenic (mostly). Alkaloids present (mostly), or absent. Iridoids recorded (in three genera); carbocyclic and seco-compounds. Proanthocyanidins present, or absent; cyanidin (mostly), or cyanidin and delphinidin. Flavonols present, or absent; when present, kaempferol, or quercetin, or kaempferol and quercetin (mostly). Ellagic acid absent (14 species, 12 genera). Ursolic acid present. Saponins/sapogenins present, or absent. Aluminium accumulation demonstrated (a few genera only), or not found (mostly). C3 and CAM. C3 recorded in Apocynum, Nerium, Pachypodium, Plumeria, Rhazya. CAM recorded in Carissa (non-succulent). Anatomy non-C4 type (Apocynum, Allamonda, Nerium, Plumeria).
Geography, cytology. Temperate (a few), or sub-tropical to tropical (mainly). Widespread. X = 8-12(+).
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren's Superorder Gentianiflorae; Gentianales. Cronquist's Subclass Asteridae; Gentianales. Takhtajan's Subclass Asteridae; Gentiananae; Gentianales. Species 1500. Genera 164; Allemanda, Alstonia, Alyxia, Amsonia, Apocynum, Arduina, Aspidosperma, Baissea, Carpodinus, Cerbera, Dipladenia, Dyera, Echites, Forsteronia, Funtumia, Hancornia, Landolphia, Lochnera, Lyonsia, Malouetia, Mendevilla, Nerium, Ochrosia, Parsonia, Pleiocarpa, Plumiera, Prestonia, Rauwolfia, Strophanthus, Tabernaemontana, Vinca, Voacanga, Wrightia etc.
Economic uses, etc. Many past, inferior commercial sources of rubber (e.g. Carpodinus, Landolphia, Mascarenhasia), numerous showy ornamentals, several sources of drugs and alkaloids, edible fruit (`Natal plum') from Carissa carandas.
Illustrations. apocy440.gif apocy549.gif
Additional, to be intercalated. Twining anticlockwise (Dipladenia).
