Bracts sentence example
Monoecious, and bearing their male flowers in catkins, they are readily distinguished from the rest of the catkin-bearing trees by their peculiar fruit, an acorn or nut, enclosed at the base in a woody cup, formed by the consolidation of numerous involucral bracts developed beneath the fertile flower, simultaneously with a cup-like expansion of the thalamus, to which the bracteal scales are more or less adherent.
With an apical pneumatophore, not divided into chambers, followed by a series of nectocalyces or bracts.
With a very large pneumatophore not divided into chambers, but without nectocalyces or bracts.
The yew-like leaves spread laterally, and are of a deep green tint; the cones are furnished with tridentate bracts that project far beyond the scales.
The large cones stand erect on the branches, are cylindrical in shape, and have long bracts, the curved points of which project beyond the scales.Advertisement
The flowers are arranged in racemes without bracts; during the life of the flower its stalk continues to grow so that the open flowers of an inflorescence stand on a level (that is, are corymbose).
The plants grow from a bulb or short rhizome; the inflorescence is an apparent umbel formed of several shortened monochasial cymes and subtended by a pair of large bracts.
The bracts are usually scale-like, but sometimes foliaceous, as for instance in Calystegia, where they are large and envelop the calyx.
The yellow stamen-bearing flowers are in sessile, nearly spherical catkins; the fertile ones vary in colour, from red or purple to greenish-white, in different varieties; the erect cones, which remain long on the branches, are above an inch in length and oblong-ovate in shape, with reddish-brown scales somewhat waved on the edges, the lower bracts usually rather longer than the scales.
The leaves are short, thicker and more rigid than in any of the other larches; the cones are much larger than those of the hackmatacks, egg-shaped or oval in outline; the scales are of a fine red in the immature state, the bracts green and extending far beyond the scales in a rigid leaf-like point.Advertisement
Plants whose beauty resides in the bracts or floral leaves which surround the inconspicuous flowers.
Characias, 2 to 3 ft., with green bracts, are fine plants for rockwork or sheltered corners.
The small drupe-like fruit is attached to the persistent bracts.
Generally, however, the flower-bearing portion of the plant is sharply distinguished from the foliage leafbearing or vegetative portion, and forms a more or less elaborate branch-system in which the bracts are small and scale-like.
The Poinsettia pulcherrima of gardens (Euphorbia pulcherrima of botanists), a native of Mexico and Central America, with its brilliant scarlet bracts, stands unrivalled amongst decorative plants.Advertisement
The latter are borne three together, invested by a cupule of four green bracts, which, as the fruit matures, grow to form the tough green prickly envelope surrounding the group of generally three nuts.
The leaf is usually provided at the base of the leaf-stalk with stipules, which are inconspicuous, or large and leafy; and the stalk is also furnished with one or more glandular excrescences, as in some cases are the leaf itself and the bracts.
The bracts on the flower-stalk are either small and scattered or large and leafy, and then placed near the flower, forming a sort of outer calyx or epicalyx.
The two bracts are, however, on different axes, one secondary to the other, and cannot therefore be parts of one whorl of organs.
Bracts of a more general character subtending branches C' of the inflorescence are singularly rare in Gramineae, in marked contrast with Cyperaceae, where they are so conspicuous.Advertisement
The persistent bracts (glume and pale) afford an additional protection to the fruit; they protect the embryo, which is near the surface, from too rapid wetting and, when once soaked, from drying up again.
Less absolute characters, but generally trustworthy and more easily observed, are the feathery stigmas, the always distichous arrangement of the glumes, the usual absence of more general bracts in the inflorescence, the split leaf-sheaths, and the hollow, cylindrical, jointed culms - some .or all of which are wanting in all Cyperaceae.
No characters for main divisions can be obtained from the flower proper or fruit (with the exception of the character of the hilum), and it has therefore been found necessary to trust to characters derived from the usually less important inflorescence and bracts.
The female heads are spinose with long pungent bracts, fall entire when ripe and are carried away by wind or sea, becoming finally anchored in the sand and falling to pieces.
After fertilization, some of the uppermost bracts below each flower become red and fleshy; the perianth develops into a woody shell, while the integument remains membranous.Advertisement
The spike of an inflorescence bears whorls of flowers at each node in the axils of concrescent bracts accompanied by numerous sterile hairs (paraphyses); in a male inflorescence numerous flowers occur at each node, while in a female inflorescence the number of flowers at each node is much smaller.
Each cone consists of an axis, on which numerous broad and thin bracts are arranged in regular rows; in the axil of each bract occurs a single flower; a male flower is enclosed by two opposite pairs of leaves, forming a perianth surrounding a central sterile ovule encircled by a ring of stamens united below, but free distally as short filaments, each of which terminates in a trilocular anther.
The crown of the pine-apple, c, consists of a series of empty bracts prolonged beyond the fruit.
In the other Calamarian strobili known the whorls of sporangiophores are separated by whorls of bracts.
The cone of Sphenophyllum consisted of an axis bearing at the nodes whorls of bracts, united below into a sheath.Advertisement
In Cheirostrobus a similar relation of sporangiophores to bracts existed, but here each bract was divided into three segments.
That these three sterile segments, with their sporangiophores, are together comparable to one of the bracts of Sphenophyllum, with its sporangiophores, is shown by the vascular supply in each case being derived from a single leaf-trace, So far as is at present known, the Sphenophyllales were homosporous.
The flowers are shortlystalked, the lower ones growing in the fork of the branches, the upper ones sessile in one-sided leafy spikes which are rolled back at the top before flowering, the leaves becoming smaller upwards and taking the place of bracts.
The generally one-seeded nut-like fruit is associated with the persistent often hardened or greatly enlarged bracts forming the so-called cupule which gives the name to the group. The group is subdivided as follows, and these subdivisions are now generally regarded either as distinct natural orders or the first two as sub-orders of one natural order.
Female flowers arranged, two to three together on scale-like structures formed by the union of bracts, in catkins; ovary two-celled; fruit small, flattened, protected between the ripened scales of the catkin.Advertisement
Female flowers in pairs, the bracts enlarging in the fruit to form a membranous cup (hazel), or a flat three-lobed structure (hornbeam).
Bracts forming a fleshy or hard cupule which envelops the one to several fruits.
Flower-buds, like leaf-buds, are produced in the axil of leaves, which are called bracts.
Bracts sometimes do not differ from the ordinary leaves, as in Veronica hederifolia, Vinca, Anagallis and Ajuga.
When the flower is sessile the bracts are often applied closely to the calyx, and may thus be confounded with it, as in the order Malvaceae and species of Dianthus and winter aconite (Eranthis), where they have received the name of epicalyx or calyculus.Advertisement
In many cases bracts act as protective organs, within or beneath which the young flowers are concealed in their earliest stage of growth.
When bracts become coloured, as in Amherstia nobilis, Euphorbia splendens, Erica elegans and Salvia splendens, they may be mistaken for parts of the corolla.
A series of empty coloured bracts terminates the inflorescence of Salvia Horminum.
The smaller bracts or bracteoles, which occur among the subdivisions of a branching inflorescence, often produce no flower-buds, and thus anomalies occur in the floral arrangements.
Bracts are occasionally persistent, remaining long attached to the base of the peduncles, but more usually they are deciduous, falling off early by an articulation.Advertisement
Thus, the cones of firs and the stroboli of the hop are composed of a series of spirally arranged bracts covering fertile flowers; and the scales on the fruit of the pine-apple are of the same nature.
At the base of the general umbel in umbelliferous plants a whorl of bracts often exists, called a general involucre, and at the base of the smaller umbels or umbellules there is a similar leafy whorl called an involucel or partial involucre.
In Compositae the name involucre is applied to the bracts surrounding the head FIG.
Such whorled or verticillate bracts generally remain separate (polyphyllous), but may be united by cohesion (gamophyllous), as in many species of Bupleurum and in Lavatera.
In Compositae besides the involucre there are frequently chaffy and setose bracts at the base of each flower, and in Dipsacaceae a membranous tube surrounds each flower.Advertisement
Bracts also compose the husky covering of the hazel-nut.
When bracts become united, and overlie each other in several rows, it often happens that the outer ones do not produce flowers, that is, are empty or sterile.
In the artichoke the outer imbricated scales or bracts are in this condition, and it is from the membranous white scales or bracts (paleae) forming the choke attached to the edible receptacle that the flowers are produced.
The sterile bracts of the daisy occasionally produce capitula, and give rise to the hen-and-chickens daisy.
In place of developing flower-buds, bracts may, in certain circumstances, as in proliferous or viviparous plants, produce leaf-buds.
Bracts are frequently changed into complete leaves.
This change is called phyllody of bracts, and is seen in species of Plantago, especially in the variety of Plantago media, called the rose-plantain in gardens, where the bracts become leafy and form a rosette round the flowering axis.
The conversion of bracts into stamens (staminody of bracts) has been observed in the case of A bies excelsa.
A lengthening of the axis of the female strobilus of Coniferae is not of infrequent occurrence in Cryptomeria japonica, larch (Larix europaea), &c., and this is usually associated with a leaf-like condition of the bracts, and sometimes even with the development of leaf-bearing shoots in place of the scales.
Exceptions, such as in cruciferous plants, are due to the non-appearance of the bracts.
According to the mode and degree of development of the lateral shoots and also of the bracts, various forms of both inflorescences result.
The flower in this case is solitary, and the ordinary leaves become bracts by producing flower-buds in place of leaf-buds; their number, like that of the leaves of this main axis, is indefinite, varying with the vigour of the plant.
If other flowers were produced, they would arise as lateral shoots from the bracts below the first-formed flower.
Sometimes, especially towards the summit of a dichasium, owing to the exhaustion of the growing power of the plant, only one of the bracts gives origin to a new axis, the other remaining empty; thus the inflorescence becomes unilateral, and further development is arrested.
The bracts are like the ordinary leaves of the plant, and produce clusters of flowers in their axil.
In the uniparous cyme a number of floral axes are successively developed one from the other, but the axis of each successive generation, instead of producing a pair of bracts, produces only one.
The false axis, a b c d, is formed by successive generations of unifloral axes, the flowers being arranged along one side alternately and in a double row; had the bracts been developed they would have formed a similar double row on the opposite side of the false axis; the whole inflorescence is represented as curved on itself.
This mixed character presents difficulties in such cases as Labiatae, where the leaves, in place of retaining their ordinary form, become bracts, and thus might lead to the supposition of the whole series of flowers being one inflorescence.
We next have flowers in which the calyx is suppressed, and its place occupied by one, two or three bracts (so that the flower is, properly speaking, achlamydeous), and only one or two stamens are produced.
Almost all strobili of the Calamarieae are constructed on the same general lines as those of Equisetum, with which some agree exactly; in most, however, the organization was more complex, the complexity consisting in the intercalation of whorls of sterile bracts, between those of the sporangiophores.
The sporangiophores, which are usually half as numerous in each verticil as the bracts, have the same form as in Equisetum, but each bears four sporangia only.
Diagrammatic longitudinal section of cone, showing the axis (ax) bearing the bracts (br) with peltate sporangiophores (sp) springing from their axils; sm, sporangia.
Part of cone, showing the axis (ax) bearing peltate sporangiophores (sp) without bracts; sm, sporangia.
In certain cases the strobili of Palaeozoic Calamarieae appear to have had essentially the same organization as in the recent genus, the axis bearing sporangiophores only, without intercalated bracts.
Other cones, however, namely, those known as Pothocites, have also been attributed on good grounds to the genus Archaeocalamites; they are long strobili, constricted at intervals, and it is probable that the succession of fertile sporangiophores was interrupted here and there by the intercalation of sterile bracts, which may also have been present, at long intervals, in Renault's species.
Weiss first showed, immediately below the verticils of bracts, the position thus being the reverse of that in Palaeostachya.
Diagrammatic longitudinal section of the cone, showing the axis (ax) bearing alternate whorls of bracts (br) and peltate sporangiophores (sp) with their sporangia (sm).
The upturned tips of the bracts are only shown in every alternate verticil.
Thus the sterile bracts of other species are here replaced by sporangium-bearing organs.
The dorsal segments are sterile, corresponding to the bracts of Sphenophyllum Dawsoni, while the ventral segments constitute peltate sporangiophores, each bearing four sporangia, just as in a ax FIG.
Some of the stamens are inserted between the bracts, in an apparently axillary position, while others are grouped about the apex of the axis.
The female inflorescences vary considerably in organization; in some species the axis of the spike bears solitary ovules, each accompanied by a few bracts, while in others the lateral appendages are catkins, each containing from two to several ovules.
A number of hairy linear bracts enclose the whole; internal to these occur 12 to 20 crowded pinnate leaves (sporophylls), with their apical portions bent over towards the axis of the flower, the bases of the petioles being fused laterally into a disk surrounding the base of the conical receptacle.
Mr Wieland's researches have, however, demonstrated the existence in flowers of this type of the remains of a disk at the base of the receptacle, between the receptacle and the surrounding bracts, to which staminate leaves were originally attached.
This means they all have their seeds enclosed in ovaries, which are surrounded by bracts (modified leaves, associated with flowers ).
In some species they are solitary, others in racemes or umbels, and some species have leafy bracts above the flowers.
Of special interest is Davidia involucrata, which produces handkerchief bracts in early summer.
Liberty pink NEW Salmon pink bracts above dark green foliage.
Large white bracts, which hang beside the small clusters of flowers, give the plant its common names.
The flower's petals are enclosed by hairy green bracts.
A miracle happened Ã¢ the red bracts that are associated with Christmas appeared on the weed.
It has pretty reddish-purple flowers growing along long bracts and is indigenous to most parts of tropical America.
In summer large, greenish yellow flower bracts are produced with a prominent black eye.
The bracts are pale green, about three times as long as in the normal type, and very shaggy.
The conspicuous large bracts have an almost silvery sheen.
It belongs to the Dogwood family, and the large white bracts are more showy than the flowers.
Inside a pair of white bracts about the size of the hand is a head of redanthered stamens, and a tree in full flower is a marvellous sight, owing to the alternate white and green caused by the large bracts intermingling with the leaves.
In D. speciosum, a Himalayan species, the small deep purple flowers are nearly smothered by the large green bracts.
The spathe bracts resemble a corolla, and consist of four large pure white spreading leaves from the base of the spadix or cone of flowers.
It is a fine subject for skeletonising, and the stems, bracts, and calyces may be skeletonised intact.
It differs from the preceding in being smooth, deep green, and dwarfer, and in having as a rule several empty bracts below the inflorescence.
It is a bold plant, standing rigidly erect to a height of 5 or 6 feet, with large heart-shaped leaves and purple Thistle-like flower heads, wrapped in overlapping bracts.
The brightly-colored "flowers" are really modified leaves called bracts.
The overlapping bracts afforded protection to the sporangia, which were borne on sporangiophores springing from the upper surface of the coherent bracts near their origin from the axis; two sporangiophores usually arose from each bract, and sometimes adhered to its upper surface for some distance.
In other species of Sphenophyllum, which are known only as impressions, single sporangia, or groups of four, appear to have been inserted directly on the upper surface of the bracts.