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The families of flowering plants

L. Watson and M.J. Dallwitz

Boraginaceae Juss.

Including Asperifoliaceae Reichb., Buglossaceae Hoffmannsegg & Link, Heliotropiaceae Schrad., Onosmaceae (Onosmataceae) Horan., Scorpiaceae Dulac; excluding Ehretiaceae, Hoplestigmataceae, Wellstediaceae.

Habit and leaf form. Trees, or shrubs, or herbs, or lianas (a few); without essential oils. Annual to perennial (often hispid or scabrid); with a basal aggregation of leaves, or without conspicuous aggregations of leaves. Self supporting (usually), or climbing. Helophytic, or mesophytic, or xerophytic. Leaves minute to medium-sized; alternate, or alternate and opposite (then opposite below); flat; ‘herbaceous’; petiolate to sessile; non-sheathing, or sheathing (sometimes, in basal rosettes); not gland-dotted; simple; epulvinate. Lamina entire; usually narrow, linear to lanceolate. Leaves exstipulate. Lamina margins entire (mostly), or crenate, or dentate. Leaf development not ‘graminaceous’. Domatia occurring in the family.

Leaf anatomy. The leaf lamina dorsiventral, or bifacial (commonly isobolateral, sometimes variable within genera). Mucilaginous epidermis absent. Stomata on both surfaces (commonly), or mainly confined to one surface (then abaxial); anomocytic (usually?), or anisocytic. Hairs usually present (of diverse forms, the herbs especially characterized by hispid leaves, attributable to thick-walled unicellular hairs); eglandular, or eglandular and glandular. Multicellular hairs uniseriate; branched, or simple. Urticating hairs absent. Adaxial hypodermis absent. Lamina without secretory cavities. Cystoliths commonly present (at the bases of the hairs). The mesophyll commonly containing crystals. The crystals raphides, or druses, or solitary-prismatic. Midrib conspicuous. Main veins vertically transcurrent, or embedded. Minor leaf veins with phloem transfer cells (usually in 17 genera), or without phloem transfer cells (Caccinea, Heliotropium).

Axial (stem, wood) anatomy. Secretory cavities absent. Cork cambium usually present; initially deep-seated, or initially superficial. Nodes unilacunar. Primary vascular tissues in a cylinder, without separate bundles; collateral. Internal phloem absent. Cortical bundles absent. Medullary bundles absent. Secondary thickening developing from a conventional cambial ring. Primary medullary rays wide (in woody species), or narrow.

The wood ring porous to semi-ring porous. The vessels very small to large. The vessel end-walls horizontal; simple (usually), or reticulately perforated. The vessels without vestured pits; without spiral thickening. The axial xylem with tracheids; commonly with vasicentric tracheids; with fibre tracheids, or without fibre tracheids; with libriform fibres, or without libriform fibres; at least sometimes including septate fibres, or without septate fibres (?). The parenchyma apotracheal. The secondary phloem not stratified. ‘Included’ phloem absent. The wood storied, or partially storied, or not storied.

Reproductive type, pollination. Plants hermaphrodite, or dioecious (sometimes in Heliotropium), or gynodioecious (e.g. in Echium). Pollination predominantly entomophilous; via hymenoptera.

Inflorescence, floral, fruit and seed morphology. Flowers aggregated in ‘inflorescences’ (nearly always), or solitary (e.g. sometimes in Heliotropium); in cymes. The ultimate inflorescence units cymose (coiled at first). Inflorescences terminal, or axillary, or leaf-opposed; usually coiled cincinnial, sometimes double; not pseudanthial. Flowers bracteate, or ebracteate; bracteolate; usually regular, or somewhat irregular to very irregular (Echium and relatives); when irregular, somewhat zygomorphic; basically 5 merous (but Plagiobothrys sometimes with supernumerary K members); cyclic; tetracyclic. Free hypanthium absent. Hypogynous disk present, or absent.

Perianth with distinct calyx and corolla; 10(–13); 2 whorled; isomerous (mostly), or anisomerous (sometimes in Plagiobothrys). Calyx 5 (usually), or 5–8 (sometimes in PLagiobothrys); 1 whorled; polysepalous, or gamosepalous (basally). Calyx lobes when gamosepalous, markedly shorter than the tube to markedly longer than the tube. Degree of gamosepaly (maximum length joined/total calyx length) 0.1–0.5. Calyx basally appendaged (e.g. Myosurus), or neither appendaged nor spurred; persistent (usually), or not persistent (sometimes in Heliotropium); imbricate, or open in bud, or valvate (rarely). Corolla 5; 1 whorled; appendiculate (often, with a corona of scales from the throat protecting the nectar), or not appendiculate; gamopetalous. Corolla lobes markedly shorter than the tube to markedly longer than the tube. Corolla imbricate, or contorted; rotate, or campanulate to hypocrateriform, or tubular; unequal but not bilabiate, or regular, or bilabiate (often, in Echium); green, or white, or yellow, or orange, or pink, or purple, or blue (or violet).

Androecium 5. Androecial members unbranched; adnate (to the corolla); all equal, or markedly unequal; free of one another, or coherent; 1 whorled. Androecium exclusively of fertile stamens. Stamens 5; inserted midway down the corolla tube, or in the throat of the corolla tube; not didynamous, not tetradynamous; isomerous with the perianth; oppositisepalous; filantherous to with sessile anthers. Filaments appendiculate, or not appendiculate. Anthers cohering, or separate from one another, or connivent (sometimes somewhat coherent at base and apex); dorsifixed to basifixed; dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged, or unappendaged. The anther appendages when present, apical, or basal. 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 ‘dicot’ type. Tapetum glandular. Pollen grains aperturate; 3–20 aperturate (to ‘many’); colpate, or porate, or colporate, or colpate and colporate (alternating); 2-celled (recorded in Heliotropium only, with Coldenia and Cordia removed to Ehretiaceae), or 3-celled (in 16 genera).

Gynoecium 2 carpelled (usually), or 4–5 carpelled (sometimes in Trigonotis). Carpels reduced in number relative to the perianth (usually), or reduced in number relative to the perianth to isomerous with the perianth (Trigonotis). The pistil 2 celled, or 4 celled (usually, via false septa), or 8–10 celled (via false septa, in some Trigonotis species). Gynoecium syncarpous; synstylovarious to eu-syncarpous; superior. Ovary 2 locular (nearly always, but only rarely ostensibly so), or 4–5 locular (and usually ostensibly four, via false septa). Locules secondarily divided by ‘false septa’ (usually), or without ‘false septa’ (rarely). Gynoecium median; stylate. Styles 1; from a depression at the top of the ovary; ‘gynobasic’, or apical (in Heliotropoideae). Stigmas 1–2; when simple, 1–2 lobed; nearly always dry type; papillate; Group II type (usually), or Group III type (rarely). Placentation axile to basal. Ovules 2 per locule (usually separating into one-ovuled portions); horizontal to ascending; epitropous (the micropyle directed upwards); with dorsal raphe; non-arillate; anatropous, or hemianatropous; unitegmic; tenuinucellate. Endothelium differentiated. Embryo-sac development Polygonum-type, or Allium-type (sometimes). Polar nuclei fusing prior to fertilization, or fusing only after one has been fertilized (?). Antipodal cells formed; 3; not proliferating; ephemeral, or persistent. Synergids pear-shaped, or hooked. Endosperm formation cellular to nuclear. Endosperm haustoria present, or absent; micropylar (Heliotropium). Embryogeny onagrad, or chenopodiad.

Fruit fleshy, or non-fleshy; when dry, dehiscent, or indehiscent, or a schizocarp. Mericarps when schizocarpic, 4, or 8–10 (sometimes, in Trigonotis); comprising nutlets, or comprising drupelets. Fruit a drupe (1–4 seeded). The drupes with separable pyrenes (two or four). Seeds endospermic, or non-endospermic. Embryo well differentiated (the radicle directed upwards, by contrast wih Labiatae). Cotyledons 2. Embryo achlorophyllous (14/17); straight, or curved.

Seedling. Germination phanerocotylar, or cryptocotylar.

Physiology, phytochemistry. C3 and C4. C3 physiology recorded directly in Arnebia, Heliotropium, Lappula, Lithospermum, Moltkiopsis, Onosmodium, Trichodesma. C4 physiology recorded directly in Heliotropium. Anatomy C4 type (Heliotropium), or non-C4 type (Arnebia, Cynoglossum, Echiochilon, Heliotropium, Heterocaryum, Lappula, Lithospermum, Myosotis, Onosma, Onosmodium, Trichodesma, Vaupelia). Inulin recorded (Cynoglossum). Cyanogenic (rarely), or not cyanogenic. Alkaloids present, or absent. Iridoids not detected. Saponins/sapogenins absent. Proanthocyanidins absent. Flavonols present (usually), or absent (Echium); kaempferol and quercetin (usually), or quercetin. Ellagic acid absent (11 species, 9 genera).

Geography, cytology. Holarctic, Paleotropical, Neotropical, Cape, Australian, and Antarctic. Temperate to tropical. Cosmopolitan, but fewer in cool temperate and tropical regions, and with a strong Mediterranean concentration. X = 4–12.

Taxonomy. Subclass Dicotyledonae; Tenuinucelli. Dahlgren’s Superorder Solaniflorae; Boraginales. Cronquist’s Subclass Asteridae; Lamiales. APG III core angiosperms; core eudicot; Superorder Asteranae; lamiid. APG IV Order Boraginales.

Species 2000. Genera about 120; Actinocarya, Adelocaryum, Afrotysonia, Alkanna, Amblynotus, Amphibologyne, Amsinckia, Anchusa, Ancistrocarya, Anoplocaryum, Antiotrema, Antiphytum, Arnebia, Asperugo, Auxemma, Borago, Bothriospermum, Brachybotrys, Brunnera, Buglossoides, Caccinia, Carmona, Cerinthe, Chionocharis, Choriantha, Craniospermum, Cryptantha, Cynoglossopsis, Cynoglossum, Cynoglottis, Cysostemon, Dasynotus, Decalepidanthus, Echiochilon, Echiostachys, Echium, Elizaldia, Embadium, Eritrichium, Euploca, Gastrocotyle, Gyrocaryum, Hackelia, Halacsya, Heliocarya, Heliotropium, Heterocaryum, Huynhia, Ivanjohnstonia, Ixorhea, Lacaitaea, Lappula, Lasiarrhenum, Lasiocaryum, Lepechiniella, Lepidocordia, Lindelophia, Lithodora, Lithospermum, Lobostemon, Macromeria, Maharanga, Mairetis, Mattiastrum, Mertensia, Metaeritrichium, Microcaryum, Microula, Mimophytum, Moltkia, Moltkiopsis, Moritzia, Myosotidium, Myosotis, Neatostema, Nesocaryum, Nogalia, Nomosa, Nonea, Ogastemma, Omphalodes, Omphalolappula, Omphalotrigonotis, Onosma, Onosmodium, Oxyosmyles, Paracaryum, Pardoglossum, Patagonula, Pectocarya, Pentaglottis, Perittostema, Plagiobothrys, Pseudomertensia, Psilolaemus, Pteleocarpa, Pulmonaria, Rindera, Rochefortia, Rochelia, Rotula, Saccellium, Scapicephalus, Selkirkia, Sericostoma, Sinojohnstonia, Solenanthus, Stenosolenium, Stephanocaryum, Suchtelenia, Symphytum, Thaumatocaryum, Thyrocarpus, Tianschaniella, Tiquilia, Tournefortia, Trachelanthus, Trachystemon, Trichodesma, Trigonocaryum, Trigonotis, Ulugbekia, Valentiniella.

General remarks. Comparing the descriptions of Hoplestigmataceae and Wellstediaceae (q..v.) with this compilation for Boraginaceae sensu stricto suggests they are well worth retaining as separate families, Ehretiaceae (q.v.) being less convincing. However, any under-estimates of variation in this compilation for Boraginaceae may call into question the taxonomic worth of the segregate families.

Economic uses, etc. Ornamentals, pot herbs, dyes for wood, stone, medicines, wines and cosmetics, and some important honey plants.


Then the blossoms blue to the bank he threw
Ere he sank in the eddying tide;
And ‘Lady, I’m gone, thine own knight true,
Forget me not’, he cried
(Bishop Mant, quoted by Ann Pratt, ‘Wild Flowers’ (1857) - Myosotis palustris)

And laden barges float
By banks of myosote
(Robert Bridges (1844–1930), ‘There is a Hill’)

Borage and Hellebore fill two scenes,
Sovereign plants to purge the veins
Of melancholy, and clear the heart
Of those black fumes which make it smart
(Burton, quoted by Ann Pratt, ‘Wild Flowers’ (1857) - Borago officinalis)

Illustrations. • Le Maout and Decaisne: Lycopsis, Pulmonaria. Myosotis. • Le Maout and Decaisne: Symphytum, Cerinthe. • Le Maout and Decaisne: Cynoglossum, Heliotrope, Tournefortia. • Boragineae (Symphytum, Borago, Anchusa, Pentaglossis: B. Ent. compilation, 1824–35). • Lithospermeae (Myosotis, Lithospermum: B. Ent. compilation, 1824–35). • Lithospermeae (Mertensia), Cynoglosseae, Echieae: B. Ent. compilation, 1824–35. • Adelocaryum anchusoides: as Cynoglossum, Bot. Reg. 14, 1842. • Anchusa arvensis and A. officinalis: Eng. Bot. 1111 and 1112, 1867. • Borago officinalis: Eng. Bot. 11141, 1867. • Cordia aspera: Seeman, Flora Vitiensis 2 (1873). • Cordia subcordata: Seeman, Flora Vitiensis 2 (1873). • Cryptantha aprica, C. gnaphalioides, C. linearis, C. phacelioides, C. volckmannii: Engler, Das Pflanzenreich 97 (1931). • Cynoglossum officinale and C. germanicum (as montanum): Eng. Bot. 1118 and 1119, 1867. • Echium vulgare and E. plantagineum: Eng. Bot. 1095 and 1096, 1867. • Eritrichium nanum: Bot. Mag. 96 (1870). • Euploca convolvulacea: Hook. Ic. Pl. 7–8 (1844). • Heliotropium amplexicaule (as H. anchusaefolium): Bot. Mag. 139 (1913). • Lindelofia longiflora: as Cynoglossum longiflorum, Bot. Reg. xxvi, 50 (1840). • Lithospermum purpureocaeruleum, L. officinale and L. arvense: Eng. Bot. 1100, 1101 and 1102, 1867. • Lithospermum rosmarinifolium: Bot. Reg. 1736, 1835. • Mertensia maritima: Eng. Bot. 1099, 1867. • Moltkia petraea: Bot. Reg. 29 (26), 1843. • Myosotis laxa (as caespitosa), M. scorpioides (as palustris), M. secunda (as repens) and M. sylvatica: Eng. Bot. 1103–1105 and 1107, 1867. • Myosotis alpestris, M. arvensis, M. ramosissima (as collina) and M. discolor (as versicolor): Eng. Bot. 1106 and 1108–1110, 1867. • Pentaglottis sempervirens: as Anchusa sempervirens, Eng. Bot. 1097, 1867. • Pulmonaria angustifolia and P. officinalis: Eng. Bot. 1097 and 1098, 1867. • Rotula aquatica, as Rhabdia viminea: Hook. Ic. Pl. 9 (1852). • Sericostoma pauciflorum: Hook. Ic. Pl. 9 (1852). • Symphytum officinale (3 varieties): Eng. Bot. 1115 and 1116, 1867. • Symphytum tuberosum: Eng. Bot. 1117, 1867. • Tournefortia elongata: Flora of Guatemala 9 (1970). • Leaf hairs and epidermal cystoliths of Lithospermum officinale (Solereder, 1908).

We advise against extracting comparative information from the descriptions. This is much more easily achieved using the DELTA data files or 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 or lacking specified attributes, distributions of character states within any set of taxa, geographical distribution, genera included in each family, and classifications (Dahlgren; Dahlgren, Clifford, and Yeo; Cronquist; APG). See also Guidelines for using data taken from Web publications.

Cite this publication as: ‘Watson, L., and Dallwitz, M.J. 1992 onwards. The families of flowering plants: descriptions, illustrations, identification, and information retrieval. Version: 15th April 2018.’.