The Families of Flowering Plants
The Families of Flowering Plants | |
~ Boraginaceae
Including Hydroleae (Hydroleaceae) R.Br.
Habit and leaf form. Herbs (usually), or shrubs (sometimes spiny); non-laticiferous and without coloured juice. Annual, biennial, and perennial; with a basal aggregation of leaves, or with neither basal nor terminal aggregations of leaves. Mesophytic. Leaves alternate, or opposite; spiral; petiolate; not connate; non-sheathing; not gland-dotted; without marked odour, or foetid; simple, or compound; when compound, pinnate, or palmate (rarely). Lamina dissected, or entire; when simple/dissected, pinnatifid; pinnately veined, or palmately veined (rarely); cross-venulate. Leaves exstipulate; without a persistent basal meristem.
Leaf anatomy. Stomata present; mainly confined to one surface, or on both surfaces; anomocytic.
Lamina dorsiventral, or isobilateral. Minor leaf veins with phloem transfer cells (5 genera), or without phloem transfer cells (Wigandia).
Stem anatomy. Cork cambium present; initially superficial. Nodes unilacunar. Secondary thickening developing from a conventional cambial ring. Xylem with tracheids, or without tracheids. Vessel end-walls simple. Wood parenchyma apotracheal (diffuse).
Reproductive type, pollination. Fertile flowers hermaphrodite. Plants hermaphrodite. Pollination entomophilous; via hymenoptera.
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’ (usually), or solitary (rarely); in cymes. The ultimate inflorescence unit cymose. Inflorescences ‘boragoid’ cincinni. Flowers often ebracteolate; regular; usually 5 merous; cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk absent (usually), or present.
Perianth with distinct calyx and corolla; (8–)10(–20); 2 whorled; isomerous. Calyx (4–)5(–10); 1 whorled; gamosepalous, or polysepalous (sometimes ‘lobes divided to the base’); regular; imbricate. Epicalyx present (as appendages between the calyx lobes), or absent. Corolla (4–)5(–10); 1 whorled; appendiculate (often having scales inside the tube, alternating with the stamens), or not appendiculate; gamopetalous; imbricate, or contorted; rotate, or campanulate, or funnel-shaped; regular; blue, or purple, or white.
Androecium (4–)5(–10) (as many as C). Androecial members adnate (to the corolla tube, and usually with basal appendages also united to the corolla, which in Hydrophyllum form tubes leading to the nectar); all equal, or markedly unequal; free of one another; 1 whorled. Androecium exclusively of fertile stamens. Stamens (4–)5(–10); inserted near the base of the corolla tube; isomerous with the perianth; oppositisepalous (alternating with the petals); alternating with the corolla members. Filaments variously, basally appendiculate. Anthers dorsifixed; versatile; dehiscing via longitudinal slits; introrse; appendaged. Microsporogenesis simultaneous. Tapetum glandular. Pollen grains aperturate; 3 aperturate, or 5–6 aperturate; colpate, or colporate, or rugate; 2-celled (in 3 genera).
Gynoecium 2 carpelled. The pistil 1 celled, or 2 celled. Gynoecium syncarpous; synovarious to synstylovarious; superior (usually), or partly inferior (sometimes). Ovary 1 locular, or 2 locular. Gynoecium median; stylate. Styles 1, or 2; free, or partially joined; attenuate from the ovary; apical. Stigmas dry type; papillate; Group II type. Placentation when unilocular, parietal; when bilocular, axile. Ovules in the single cavity when unilocular, 2–100 (i.e. to ‘many’); when bilocular 2–50 per locule (i.e. to ‘many’); funicled, or sessile; pendulous (when funicled); epitropous (the micropyle directed upwards and outwards); non-arillate; anatropous, or amphitropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells formed, or not formed (then the three nuclei degenerating early — Hydrolea); when formed, 3; not proliferating; ephemeral. Synergids sometimes with filiform apparatus. Endosperm formation cellular, or nuclear, or cellular to nuclear. Embryogeny solanad.
Fruit non-fleshy; dehiscent (usually), or indehiscent; a capsule, or capsular-indehiscent. Capsules when dehiscent, loculicidal (usually), or splitting irregularly, or septicidal (rarely). Seeds copiously endospermic. Endosperm oily. Cotyledons 2. Embryo chlorophyllous (1/1), or achlorophyllous (1/2); straight (spathulate or linear).
Seedling. Germination phanerocotylar.
Physiology, biochemistry. Not cyanogenic. Alkaloids absent (6 species). Iridoids not detected. Proanthocyanidins absent. Flavonols present; kaempferol and quercetin. Ellagic acid absent (2 genera). Saponins/sapogenins present (rarely), or absent. Aluminium accumulation not found. C3. C3 physiology recorded directly in Ellisia.
Geography, cytology. Temperate to tropical. Widespread. X = 5–13(+).
Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Solaniflorae; Boraginales. Cronquist’s Subclass Asteridae; Solanales. APG 3 core angiosperms; core eudicot; Superorder Asteranae; lamiid; Order Solanales (as a synonym of Boraginaceae).
Species 250. Genera 17; Codon, Draperia, Ellisia, Emmenanthe, Eriodictyon, Eucrypta, Hesperochiron, Hydrolea, Hydrophyllum, Nama, Nemophila, Phacelia, Pholistoma, Romanzoffia, Tricardia, Turricula, Wigandia.
Illustrations. • Technical details: Hydrophyllum, Phacelia, Ellisia. • Technical details: Hydrolia, Wigandia. • Hydrolea spinosa: Bot. Reg. 566, 1821. • Nemophila menziesii var. atomaria: as N. atomaria, Bot. Reg. 1940, 1837. • Nemophila phacelioides: Bot. Reg. 740, 1823. • Phacelia divaricata: as Eutoca, Bot. Reg. 1784, 1836. • Phacelia tanacetifolia: Bot. Reg. 1696, 1835. • Phacelia viscida: as Eutoca, Bot. Reg. 1808, 1836. • Wigandia caracasana: Bot. Reg. 1966, 1837.
This description is offered for casual browsing only. We strongly advise against extracting comparative information from it. This is much more easily achieved using the interactive key, which allows access to the character list, illustrations, full and partial descriptions, diagnostic descriptions, differences and similarities between taxa, lists of taxa exhibiting specified attributes, summaries of attributes within groups of taxa, geographical distribution, genera included in each family, classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG), and notes on the APG classification.
Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 25th November 2009. http://delta-intkey.com’.
