Boraginaceae

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Read about Boraginaceae in the Standard Cyclopedia of Horticulture 

Boraginaceae (from the genus Borago, an ancient name having reference to the roughness of the foliage). Borage Family. Fig. 51. Herbs, rarely shrubs or trees: leaves usually alternate, very frequently rough-hairy: flowers bisexual, regular, rarely irregular; inflorescence usually circinate; calyx 4-5-cleft, persistent; corolla 4-5-lobed, gamopetalous, hypogynous, imbricated, often with scales or folds in the throat; stamens 5, epipetalous, alternating with the corolla-lobes; hypogynous disk usually present; carpels 2; ovary superior, 4-celled, either entire and style terminal, or 2-lobed, or more commonly deeply 4-lobed with the style basal between the lobes; each cell 1-ovuled; style 1; stigmas usually 2: fruit rarely a berry, usually of 4 1-seeded nutlets, with the surface variously smooth, polished, wrinkled, barbed, winged, or crested.

There are 85 genera and about 1,500 species widely distributed in the temperate and tropical zones, most abundant in the Mediterranean region and in western North America. The largest genera are Cordia with 230 species, and Heliotropium with 220 species. The family is most closely related to the Hydrophyllaceae; also related to the Verbenaceae and Labiatae. The circinate inflorescence, and 2-carpelled, 4-celled ovary with 1 seed in each cell, are distinctive characteristics. The fruit of the Boraginaceae is most diverse, and very important in classification within the family.

Many species, native in Europe, were formerly used for medicine; for example, comfrey (Symphytum officinale), borage (Borago officinalis), hound's-tongue (Cynoglossum officinale), lungwort (Pulmonaria officinalis), viper's bugloss (Echium vulgare), bugloss (Anchusa officinalis), gromwell (Lithospermum officinale), and heliotrope (Heliotropium europaeum). Tournefortia umbellata was used in Mexico as a febrifuge. The roots of alkanet (Alkanna tinctoria) of South Europe and Asia contain a red dye of commercial importance. The roots of some species of Anchusa, Onosma, Lithospermum and Arnebia also contain a red pigment. The wood of some species of Cordia is of value, as are also its bast fibers. The wood of several species of Ehretia is valuable, and the fruit is edible.

About 30 genera are in cultivation in N. America, mostly as hardy ornamental border plants. Among these are: Arnebia (Prophet's Flower, Arabian Primrose); Anchusa (Alkanet, not the real); Borago (Borage), used as a pot-herb or bee-plant; Cerinthe (Honey-wort); Cynoglossum (Hound's-tongue); Echium (Viper's Bugloss); Lithospermum (Gromwell, Puccoon, Indian Paint); Myosotidiom (Giant Forget-me-not); Myosotis (Forget-me-not); Mertensia (Virginian Cowslip, Virginian Lungwort); Omphalodes (Navelwort, Creeping Forget-me-not); Onosma (Golden Drops); Onosmodium (Fake Gromwell); Pulmonaria (Lungwort, Bethlehem Sage); and Symphytum (Comfrey).

CH


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Boraginaceae
Forget-me-not (Myosotis discolor)
Forget-me-not (Myosotis discolor)
Plant Info
Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Family: Boraginaceae
Juss.

Genera
many, see text

Boraginaceae Juss. 1789, the Borage or Forget-me-not family, includes a variety of shrubs, trees, and herbs, totaling about 2,000 species in 100 genera found worldwide. A number of familiar plants belong to this family.

The Boraginaceae belong, according to the APG II, among the euasterid I group including the orders Gentianales, Lamiales, and Solanales, but whether they should be assigned to one of these orders or to their own (Boraginales) is still uncertain. Under the older Cronquist system they were included in the Lamiales, but it is now clear that they are no more similar to the other families in this order than they are to families in several other asterid orders. The Boraginaceae are paraphyletic with respect to Hydrophyllaceae and the latter is included in the former in APG II system. In some recent classifications the Boraginaceae are broken up into several families: Boraginaceae s.s., Cordiaceae, Ehretiaceae, Heliotropiaceae, Hydrophyllaceae, and Lennoaceae.

Most though not all members of this family have hairy leaves. The coarse character of the hairs is due to Silicon dioxide and Calcium carbonate. In some species, Anthocyanins cause the flowers to change their color from red to blue when aging. This is likely used as a signal to pollinators that these old flowers are depleted of pollen and nectar (Hess, 2005).

Well-known members include:

Genera

 
Boraginaceae

References

  • Diane, N., H. Förther, and H. H. Hilger. 2002. A systematic analysis of Heliotropium, Tournefortia, and allied taxa of the Heliotropiaceae (Boraginales) based on ITS1 sequences and morphological data. American Journal of Botany 89: 287-295 (online abstract here).
  • Gottschling, M., H. H. Hilger 1, M. Wolf 2, N. Diane. 2001. Secondary Structure of the ITS1 Transcript and its Application in a Reconstruction of the Phylogeny of Boraginales. Plant Biology (Stuttgart) 3: 629-636.
  • Hess, Dieter. 2005. Systematische Botanik. ISBN 3-8252-2673-5

External links

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