Family Primulaceae
Primulaceae Vent.Including Anagallidaceae Baudo, Lysimachieae (Lysimachiaceae) Juss., Samolineae (Samolaceae) Dum.Excluding Coridaceae, Myrsinaceae, Theophrastaceae Habit and leaf form. Herbs; with coloured juice, or non-laticiferous and without coloured juice. Perennial (commonly), or annual; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves; often rhizomatous, or tuberous. Hydrophytic (Hottonia), or helophytic to xerophytic (many alpine); the hydrophytic Hottonia rooted. Leaves alternate, or opposite, or whorled; when alternate, spiral; petiolate to sessile; non-sheathing; gland-dotted (seemingly infrequently, e.g. in some Anagallis species), or not gland-dotted (mostly); simple. Lamina entire (usually), or dissected; in Hottonia, pinnatifid; pinnately veined, or palmately veined; cross-venulate. Leaves exstipulate. Lamina margins crenate to dentate (usually), or entire. Leaves without a persistent basal meristem. Leaf anatomy. Hydathodes commonly present. Stomata present; anomocytic. Lamina dorsiventral (usually), or centric; with secretory cavities, or without secretory cavities. Secretory cavities schizogenous, or lysigenous (with red contents). The mesophyll generally without calcium oxalate crystals. Minor leaf veins with phloem transfer cells (variably so, in Anagallis only), or without phloem transfer cells (Anagallis, Auricula, Cyclamen, Dodecatheon, Glaux, Lysimachia, Primula, Samolus, Sodanella). Stem anatomy. Secretory cavities present, or absent (?). Cork cambium present, or absent (?); initially deep-seated, or superficial. Nodes unilacunar. Primary vascular tissue in a cylinder, without separate bundles, or comprising a ring of bundles, or in two or more rings of bundles to in scattered bundles. Secondary thickening absent, or developing from a conventional cambial ring, or anomalous (Hottonia, Primula p.p.). Xylem with libriform fibres; with vessels. Vessel end-walls simple. Sieve-tube plastids S-type. Reproductive type, pollination. Plants hermaphrodite; often heterostylous. Pollination entomophilous. Inflorescence, floral, fruit and seed morphology. Flowers solitary, or aggregated in ‘inflorescences’; in heads, in umbels, and in panicles. Inflorescences scapiflorous (often), or not scapiflorous; terminal (commonly), or axillary; umbels, panicles or heads. Flowers ebracteolate; small, or medium-sized; regular; (3–)5(–9) merous; cyclic; tetracyclic, or pentacyclic. Free hypanthium absent. Perianth with distinct calyx and corolla (usually), or sepaline (the corolla absent in Glaux); (6–)10(–18); 2 whorled (usually), or 1 whorled; isomerous. Calyx (3–)5(–9); 1 whorled; gamosepalous; regular; persistent (usually); imbricate, or contorted (e.g. Anagallis); with the median member posterior. Corolla (3–)5(–9); 1 whorled; appendiculate (with staminodal scales), or not appendiculate; gamopetalous; imbricate, or contorted; regular; green, or white, or yellow, or red, or red, or purple, or blue. Petals deeply bifid to bilobed, or entire. Androecium (3–)5(–9), or 10. Androecial members adnate (to the corolla); free of one another; 1 whorled, or 2 whorled. Androecium exclusively of fertile stamens, or including staminodes (e.g. the antesepalous scales of Samolus and Soldanella). Staminodes when present, 4–6 (alternating with the stamens); when identifiable, external to the fertile stamens (in the sense of being inserted higher on the corolla); when present, petaloid to non-petaloid (‘scales’, or similar to the staminal filaments). Stamens (3–)5(–9); inserted near the base of the corolla tube, or midway down the corolla tube, or in the throat of the corolla tube; isomerous with the perianth; alternisepalous; opposite the corolla members. Anthers dehiscing via pores, or dehiscing via longitudinal slits; introrse; tetrasporangiate. Endothecium developing fibrous thickenings. Microsporogenesis simultaneous. The initial microspore tetrads tetrahedral. Anther wall initially with one middle layer. Tapetum glandular. Pollen grains aperturate; (2–)3 aperturate, or 3–10 aperturate; colpate (3–10), or colporate (then usually tricolpate or -colporoidate, sometimes syn- or parasyncolpate); 2-celled (in 6 genera). Gynoecium supposedly 5 carpelled. Carpels usually isomerous with the perianth. The pistil 1 celled. Gynoecium syncarpous; eu-syncarpous; superior (usually), or partly inferior (Samolus). Ovary 1 locular (and no evidence of partitions). Gynoecium stylate. Styles 1; attenuate from the ovary; apical. Stylar canal present. Stigmas 1 (simple); dry type; papillate, or non-papillate; Group II type. Placentation free central. Ovules in the single cavity (5–)7–100 (usually ‘many’); ascending; non-arillate; anatropous, or hemianatropous; bitegmic; tenuinucellate. Outer integument contributing to the micropyle. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing only after one has been fertilized, or fusing simultaneously with the male gamete (?). Antipodal cells formed; 3; not proliferating. Synergids elongated. Endosperm formation nuclear. Embryogeny caryophyllad. Fruit non-fleshy; dehiscent (usually), or indehiscent (rarely); a capsule (usually), or capsular-indehiscent. Capsules valvular, or denticidal (usually five valved and dehiscing by apical teeth), or circumscissile (rarely). Fruit (1–)2–100 seeded (i.e. to ‘many’). Seeds endospermic. Endosperm oily. Seeds with amyloid. Cotyledons 1 (Cyclamen), or 2; semi-cylindric. Embryo achlorophyllous (5/10); straight. Seedling. Germination phanerocotylar. Physiology, biochemistry. Not cyanogenic. Alkaloids present (rarely), or absent. Iridoids not detected. Proanthocyanidins present (nearly always), or absent (Soldanella); cyanidin, or cyanidin and delphinidin. Flavonols present; kaempferol and quercetin, or kaempferol, quercetin, and myricetin. Ellagic acid present (Hottonia), or absent (usually — 14 species, 7 genera). Arbutin absent. Saponins/sapogenins present, or absent. Aluminium accumulation not found. C3. C3 physiology recorded directly in Anagallis, Androsace, Lysimachia, Primula. Anatomy non-C4 type (Androsace, Lysimachia, Samolus). Geography, cytology. Frigid zone to tropical. Widespread, but centred in the North temperate. X = 5, 8–15, 17, 19, 22. Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Primuliflorae; Primulales. Cronquist’s Subclass Dilleniidae; Primulales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; Order Ericales. Species 1000. Genera 20; Anagallis, Androsace, Ardisiandra, Bryocarpum, Cortusa, Cyclamen, Dionysia, Dodecatheon, Glaux, Hottonia, Kaufmannia, Lysimachia, Omphalogramma, Pelletiera, Pomatosace, Primula, Samolus, Soldanella, Stimpsonia, Trientalis. After analysing a combination of nucleic acid sequences from the chloroplast genes rbcL, ndhF andatpB, Källersjö et al (2000) support earlier claims that Primulaceae and Myrsinaceae as traditionally circumscribed are paraphyletic, with (e.g.) Anagallis, Ardisiandra, Coris, Lysimachia and Trientalis belonging in myrsinaceous rather than primulaceous clades. Rather than merging all the genera into one supposedly monophyletc family, Anderberg et al (2000) propose raising Maesa to family rank, and adjusting the contents of Myrsinaceae and Primulaceae. Samolus (with staminodes and semi-inferior overy) may be better referred to Theophrastaceae (q.v. Illustrations. Quotations . . . Pale primroses, On her left breast In the wood where often you and I Where the bee sucks, there suck I, The flowery May, who from her green lap throws Yellow Lysimachius, to give sweet rest |
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