Among these may be noticed thin strips of willow and cane and the fronds of numerous palms. "Brazilian" hats made from the fronds of the palmetto palms, Sabal palmetto and S.
The blanched fronds are also sold in large quantities for the processions of Palm Sunday, and after they have received the blessing of the priest they are regarded throughout Spain as certain defences against lightning.
2), in which the fronds fall off FIG.
If during this process part of the fronds run together, the beauty of the specimen may be restored by dipping the edge into water, so as to float out the part and allow it to subside naturally on the paper.
It is represented in Britain by four species of Lemna, and a still smaller and simpler plant, Wolfa, in which the fronds are only one-twentieth of an inch long and have no roots.
P. dryopteris, generally known as oakfern, is a very graceful plant with delicate fronds, 6 to 12 in.
Cristatum is a handsome variety with fronds forking at the apex and the tips of all the pinnae crested and curled.
P. phegopteris (beechfern) is a graceful species with a black, slender root-stock, from which the pinnate fronds rise on long stalks, generally about 12 in.
The fronds of some of these Carboniferous ferns are almost identical with those of living species.
- Stems tuberous or columnar, not infrequently branched, rarely epiphytic (Peruvian species of Zamia); fronds pinnate, bi-pinnate in the Australian genus Bowenia.
Similarly, the dead fronds fall off,leaving a ragged petiole, which is afterwards separated from the stem by an abscess-layer a short distance above the base.
From the lower part of a carpel are produced several laterally placed ovules, which become bright red or orange on ripening; the bright fleshy seeds, which in some species are as large as a goose's egg, and the tawny spreading carpels produce a pleasing combination of colour in the midst of the long dark-green fronds, which curve gracefully upwards and outwards from the summit of the columnar stem.
In Cycas the stem apex, after producing a cluster of carpellary leaves, continues to elongate and produces more budscales, which are afterwards pushed aside as a fresh crown of fronds is developed.
When found detached these leaves were taken for the fronds of a Fern.
The thick armour of petiole-bases enveloping the stem is a characteristic C y cad c an feature; in Cycas the alternation of scale-leaves and fronds is more clearly shown than in other cycads; in Encephalartos, Dioon, &e., From a photograph of a plant in the Peradeniya the persistent scale - leaf Gardens, Ceylon, by Professor R.
All round its head and also along the body the skin bears fringed appendages resembling short fronds of sea-weed, a structure which, combined with the extraordinary faculty of assimilating the colour of the body to its surroundings, assists this fish greatly in concealing itself in places which it selects on account of the abundance of prey.
Such ferns as Gymnogrammas, which have their surface covered with golden or silver powder, and certain species of scalysurfaced Cheilanthes and Nothochlaena, as they cannot bear to have their fronds wetted, should never be syringed; but most other ferns may have a moderate sprinkling occasionally (not necessarily daily) and as the season advances sufficient air and light must be admitted.
Or more broad; the tops of the fronds are fertile, the fertile pinnae being cylindrical and densely covered with the spore-cases, giving the appearance of a dense panicle of flowers, whence the plant is known as the flowering fern.
There are various cultivated forms - cristata has the ends of the fronds and the pinnae finely crested, and corymbifera has curiously forked and crested fronds.
The great majority of specimens of fossil fern-like plants are preserved in the form of carbonaceous impressions of fronds, often of remarkable perfection and beauty.
It is, however, probable that a considerable group of true Ferns, allied to Marattiaceae, existed in Palaeozoic times, side by side with simpler forms. In one respect the fronds of many Palaeozoic Ferns and Pteridosperms were peculiar, namely, in the presence on their rachis, and at the base of their pinnae, of anomalous leaflets, often totally different in form and venation from the ordinary pinnules.
Typically Marattiaceous sori, consisting of exannulate sporangia united to form synangia, are frequent, and are almost always found on fronds with the character of Pecopteris, large, repeatedly pinnate leaves, resembling those of Cyatheaceae or some species of Nephrodium.
There is evidence that in many cases these Pecopteroid fronds belonged to arborescent plants, the stems on which they were borne reaching a height of as much as 60 ft.
The genus Asterotheca includes a number of Ferns, chiefly of Coal Measure age, with fronds of the Pecopteris type.
In many fern-like plants of this period the fronds were dimorphic, the fertile leaves or pinnae having a form quite different from that of the vegetative portions.
There is evidence that the stem in some species was a climbing one; the pinnate leaves, arranged on the stem in a two-fifths spiral, were dimorphic, the sterile fronds resembling some forms of (From a drawing by Mrs D.
A number of genera of Palaeozoic " fern-fronds " have been described, of the fructification of which nothing is known.
In such cases, as will be explained below, there is a strong presumption that the fronds were not those of Ferns, but of seed-bearing plants of the new class Pteridospermeae.
Have had a habit not unlike (X 5.) that of tree-ferns, with compound leaves of enormous dimensions, belonging to various frondgenera - especially, as has now been proved, to Alethopteris and Neuropteris; these are among the most abundant of the Carboniferous fronds commonly attributed to Ferns, and extend back to the Devonian.
In 1905 Grand' Eury discovered the seeds of Pecopteris Pluckeneti, an Upper Coal Measure species, attached, in immense numbers, to the fronds, which are but little modified as compared with the ordinary vegetative foliage.
There is reason to believe that other species of Pecopteris and similar genera, (Callipteris and Mariopteris) bore seeds, though the artificial group Pecopterideae probably also includes the fronds of true Marattiaceous Ferns.
The class, though clearly allied to the typical Gymnosperms, may be kept distinct for the present on account of the relatively primitive characters shown in the anatomy and morphology, and may be provisionally defined as follows: plants resembling Ferns in habit and in many anatomical characters, but bearing seeds of a Cycadean type; seeds and microsporangia borne on fronds only slightly modified as compared with the vegetative leaves.
Archaeocalamites, Bothrodendron, Archaeopteris, Megalopteris, &c. Among fern-like fronds Diplotmema and Rhacopteris are characteristic. Some of the Lepidodendreae appear to approach Sigillariae in external characters.
Numerous fronds such as Alethopteris Neuropteris, Mariopteris, &c., belonged to Pteridosperms, of which specimens showing structure are frequent in certain beds.
The change in the character of the vegetation was con which have generally been regarded as the fronds of ferns characterized by a central midrib giving off lateral veins which repeatedly anastomose and form a network, like that in the leaves of Antrophyum, an existing member of the Polypodiaceae.
The genus possessed small broadly oval or triangular leaves in addition to the large fronds like that shown in fig.
The Bunter sandstones of the Vosges have afforded several species of Lower Triassic plants; these include the Equisetaceous genus Schizoneura - a member also of the Glossopteris flora - bipinnate fern fronds referred to the genus Anomopteris, another fern, described originally as Neuropteris grandifolia, which agrees very closely with a southern hemisphere type (Neuropteridium validum, fig.
P. Jaegeri), represented by large pinnate fronds not unlike those of existing species of Zamia, some Equisetaceous plants and numerous Ferns which may be referred to such families as Gleicheniaceae, Dipteridinae and Matonineae.
Among the large number of Mesozoic Ferns there are several species founded on sterile fronds which possess but little interest Filicales, from a botanical standpoint.
As examples of these doubtful forms may be mentioned Thinnfeldia, characteristic of Rhaetic and Lower Jurassic rocks; Dichopteris, represented by some exceptionally fine Jurassic specimens, described by Zigno, from Italy; and Ctenis, a genus chiefly from Jurassic beds, founded on pinnate fronds like those of Zamia and other Cycads, with linear pinnae characterized by anastomosing veins.
5, A), a characteristic Yorkshire fossil of Jurassic age, which in the form of the frond, bearing broad and relatively short pinnae, exhibits a striking agreement with the sterile portions of the fronds of Aneimia rotundifolia, a member of the fern family Schizaeaceae.
5, B), suggests a comparison with fern fronds like that of the recent species Nephrolepis Duffi.
It has been found useful in some cases to examine microscopically the thin film of coal that often covers the pinnae of fossil fronds, in order to determine the form of the epidermal cells which may be preserved in the carbonized cuticle; rectilinear epidermal cell-walls are usually considered characteristic of Cycads, while cells with undulating walls are more likely to belong to Ferns.
Leaving out of account the numerous sterile fronds which cannot be certainly referred to particular families of Ferns, there are several genera which bear evidence in their sori, and to some extent in the form of the leaf, of their relationship to existing types.
Bipinnate sterile fronds of Todites have in some instances been described under the designation Pecopteris whitbiensis.
Nebbense, Asplenites Roes- serti,&c.,have been given to bipinnate fronds of a type frequently met with in different genera and families of recent Ferns, e.g.
The dichotomously-branched fronds, of the type represented by several recent species of Gleichenia, e.g.
The numerous species of fronds from Jurassic and Wealden rocks of North America and Europe referred to Thyrsopteris, a recent monotypic genus confined to Juan Fernandez, are in the majority of cases founded on sterile leaves, and of little or no botanical value.
This type is distinguished by its large bipinnate fronds bearing long and narrow pinnae with close-set pinnules, characterized by the anastomosing secondary veins.
Similarly, the genus Sagenopteris, characterized by a habit like that of Marsilia, and represented by fronds consisting of a few spreading broadly oval or narrow segments, with anastomosing veins, borne on the apex of a common petiole, is abundant in rocks ranging from the Rhaetic to the Wealden, but has not so far been satisfactorily placed.
Even ice begins with delicate crystal leaves, as if it had flowed into moulds which the fronds of waterplants have impressed on the watery mirror.
2) (P. vulgare) is widely diffused in the British Isles, where it is found on walls, banks, trees, &c.; the creeping, densely-scaly rootstock bears deeply pinnately cut fronds, the fertile ones bearing on the back.
Cornubiense is a very elegant plant with finely-divided fronds; var.
The young leaves arise on the stem-apex as conical protuberances with winged borders, on which the pinnae appear as rounded humps, usually in basipetal order; the scale-leaves in their young condition resemble fronds, but the lamina remains undeveloped.
Various other seeds of the same type are known, and in a great number of instances Grand' Eury has found the fronds of Neuropterideae (Medulloseae) in close association with definite species of seeds, so there can be little doubt that the whole family was seed-bearing.
This Jurassic species bore bipinnate fronds not unlike those of the South African, Australian, and New Zealand Fern Todea barbara, which were characterized by a stout rachis and short broad pinnules bearing numerous large sporangia covering the under surface of the lamina.
Not unlike the runner, though growing in a very different way, are the bud-plants formed on the fronds of several kinds of ferns belonging to the genera Asplenium, Woodwardia, Polystichum, Lastrea, Adiantum, Cystopteris, &c. In some of these (Adiantum caudatusn, Polystichum lepidocaulon) the rachis of the frond is lengthened out much like the string of the strawberry runner, and bears a plant at its apex.
Such ferns as Gymnogrammes, which have their surface covered with golden or silver powder, and certain species of scaly-surfaced Cheilanthes and Nothochlaena, as they cannot bear to have their fronds wetted, should never be syringed; but most other ferns may have a moderate sprinkling occasionally (not necessarily daily), and as the season advances, sufficient air and light must be admitted to solidify the tissues.
In Cystopteris the buds are deciduous, falling off as the fronds acquire maturity, but, if collected and pressed into the surface of a pot of soil and kept close, they will grow up into young plants the following season.
The zoarium may rise up into erect growths composed of a single layer of zooids, the orifices of which are all on one surface, or of two layers of zooids placed back to back, with the orifices on both sides of the fronds or plates.