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BORAGINACEAE

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Originally appearing in Volume V04, Page 243 of the 1911 Encyclopedia Britannica.
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BORAGINACEAE , an See also:

order of See also:plants belonging to the sympetalous See also:section of See also:dicotyledons, and a member of the See also:series Tubiflorae. It is represented in See also:Britain by bugloss (Echium) (fig. 1), comfrey (Symphytum), Myosotis, hounds-See also:tongue (Cynoglossum) (fig. 2), and other genera, while See also:borage (Borago cfficinalis) (fig. 3) occurs as a See also:garden See also:escape in See also:waste ground. The plants are rough-haired See also:annual or perennial herbs, more rarely shrubby or arborescent, as in Cordia and Ehretia, which are tropical or sub-tropical. The leaves, which are generally alternate, are usually entire and narrow: the See also:radical leaves in some genera, as Pulmonaria (lungwort) and Cynoglossum, differ in See also:form from the See also:stem-leaves, being generally broader and some-times See also:heart-shaped. A characteristic feature is the one-sided (See also:dorsiventral) inflorescence, well illustrated in forget-me-not and other See also:species of Myosotis; the cyme is at first closely coiled, becoming uncoiled as the See also:flowers open. At the same See also:time there is often a See also:change in See also:colour in the flowers, which are red in bud, becoming See also:blue as they expand, as in Myosotis, Echium, Symphytum and others. The flowers are generally See also:regular; the form of the corolla varies widely. Thus in borage it is rotate, tubular in comfrey, See also:funnel-shaped in hounds-tongue, and See also:salver-shaped in See also:alkanet (Anchusa); the See also:throat is often closed byscale-like outgrowths from the corolla, forming the so-called See also:corona. A departure from the usual regular corolla occurs in Echium and a few allied genera, where it is oblique; in Lycopsis it is also See also:bent.

The five stamens alternate in position with the lobes of the corolla. The ovary, of two carpels, is seated on a See also:

ring-like disk I. Single See also:flower, about nat. See also:size. 6. Calyx surrounding nutlets. 2. Corolla split open. 3. Calyx. 4. See also:Pistil. 5.

One stamen. which secretes See also:

honey. median constriction in ovule; the See also:style springs divisions. The flowers show well-marked See also:adaptation to See also:insect-visits. Their colour and tendency to arrangement on one See also:surface, with the presence of honey, serve to attract See also:insects. The scales around the throat of the corolla protect the See also:pollen and honey from wet or undesirable visitors, and by their difference in colour from the corolla-lobes, as in the yellow See also:eye of forget-me-not, may serve to indicate the position of the honey. In most genera the See also:fruit consists of one-seeded nutlets, generally four, but one or more may be undeveloped. The shape of the nutlet and the See also:character of its coat are very varied. Thus in Lithospermum the nutlets are hard like a See also:stone, in Myosotis usually polished, in Cynoglossum covered with bristles, &c. The order is widely spread in temperate and tropical regions, and contains 85 genera with about 1200 species. Its See also:chief centre is the Mediterranean region, whence it extends over central 7. Same See also:part of calyx cut away. 8.

Two nutlets. 9. Same enlarged. Each carpel becomes divided by a four portions, each containing one from the centre of the See also:

group of four See also:Europe and See also:Asia, becoming less frequent northwards. A smaller centre occurs on the Pacific See also:side of See also:North See also:America. The order is less See also:developed in the See also:south temperate See also:zone. The order is of little economic value. Several genera, such as borage and Pulmonaria, were formerly used in See also:medicine, and the roots yield See also:purple or See also:brown dyes, as in Alkanna tinctoria (alkanet). See also:Heliotrope or See also:cherry-See also:pie (Heliotropium peruvianum) is a well-known garden plant.

End of Article: BORAGINACEAE

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