This is the most peculiar and mysterious class of ferns. Their modern representatives in a number of ways differ significantly from typical ferns, and their history is unknown, although it is undoubted that this group is very ancient. The cooper class includes one cooper (Ophioglossales) order, one cooper family (Ophioglossaceae), and 3 genera - the cooper (Ophioglossum), the hawthorn (Botrichium), and helminthostachis (Helmintostachys) (Fig. 60).
The scarcity of this class — 3 genera and 87 species — also indicates the antiquity of this group.
Most species are confined to the tropics, the monotypic genus helminthostachis lives in the tropical forests of the Eastern Hemisphere, and the hawthorn is found on all continents, although it gravitates to the Northern Hemisphere. In spite of antiquity, edibles are not only confined to shaded forests, but grow in meadows, swamps, and in tundra communities.
All species of ozhnikovyh plants are perennial, often evergreen plants of small sizes (20-30 cm), only one tropical epiphytic species of a cooper - a drooling coop (Ophioglossum pendulum) reaches 2-4 m. They have short rhizomes with thick, fleshy, unbranched roots, which says about their primitiveness. Each year, 1 leaf is formed on the rhizome, rarely 2 leaves, which differ from all ferns in the absence of a cochlea, prolonged (for 4-5 years) underground development and dichotomous branching of the petiole. In addition, the leaves of the cooper are not formed from one cell, like all ferns, but from a group of cells. Dillorphism of parts of the leaf is characteristic of the leaves of ovovnikovy.
Spore-bearing and vegetative lobes of leaves are located in mutually perpendicular planes, like rhinophytes telomes. In some species, the vegetative part of the leaf branches many times, in others they are whole (in species of the sprig), the same applies to spore-bearing parts. The stem part of the rhizome is constructed as a dictostele, less often an ectoflame siphon stela. It is noteworthy that in some species of pooper, the leaf petiole at the base has a radial structure and is also built as a dictostele. Metaxilema consists of stair, often point tracheids with bordered pores, similar to the xylem of gymnosperms. However, the most distinctive feature of the stem is the presence of cambium, not typical of typical ferns. The multilayer secondary xylem consists of point tracheids with a predominance of wood parenchyma.
Opochnikov sporangia occupy a marginal or apical position on leaf segments, they are massive, without a ring. The sporangia peduncle is multi-layered with an average vein suitable for sporangia, which brings the pedicle closer to the spore-bearing body. Stomata are found in the walls of sporangia, which indicates the primitiveness of sporangia. Spores are capable of a long period of rest and germinate only in the dark.
Gametophytes of the Ozhnovikovs lead an underground life. In their form, they can be worm-shaped, tuberous, or coral-shaped. In different species, their sizes range from 1 mm to 5-6 cm. Gametophytes are devoid of rhizoids and feed on mycotrophically. The rate of embryo development in different species varies from 1 year to 10-20 years. Antheridia are the first to mature, they are large, contain up to 100 sperm and open passively. Archegonies arise somewhat later. From the zygote, a haustorium develops first, and then an embryo. In some species, the leaf and bud are formed first, and the root occurs later, in other species, the roots are formed first, and later shoots.
The whole complex of distinctive features of the ozhnikovykhs gives rise to a number of authors to consider them either as descendants of the seedling or as a completely independent, very ancient dead-end line of evolution that developed parallel to ferns and seedling plants.
Ministry of Education and Science of the Russian Federation
· The Department. Fern - Polypodiophyta.
· Group. Pre-Seed - Progymnospermae
· Order. Protopteridium Protopteidales
· Family. Protopteridium Protopteidaceae
· Kind. Protopteridium - Protopteridium
· Family. Aneurrophytic - Aneurophytaceae
· Order. Archaeopteridia - Archaeopteridales
· Family. Archeopteris - Archaeopteridaceae
· Kind. Archeopteris - Archeopteris
· Order. Protopitium - Protopityales
· Order. Racophyte - Rhacophytales
· Class. The widows -Ophioglossopsida
· Family.The widows -Ophioglossaceae
· Class. Polypodiaceae - Polypodiopsida
· Class. Neggeratiopsida - Noeggerathiopsida
· Class. Zigopteridopsida - Zigopteridopsida
· Order. Zygopteris - Zygopteridales
· Kind. Etopteris - Etapteris
· Order. Anachoropteris - Anachoropteridales
· Family. Botriopteris - Botriopteridaceae
· Kind. Botriopteris - Botriopteris
· Family. Anachoropteris - Anachopteridaceae
· Order. Stavroperis - Stauropteridales
· Rod Stavroperis - Stauropteris
Representatives belonging to this class, by their characteristics, certainly should be considered very primitive representatives of ferns. However, there is no data on fossil remains from this peculiar group. It is believed that they originate from the equally spontaneous and very primitive Paleozoic ferns, the so-called pro-ferns, or, according to a more modern classification, from representatives of aneurophitopsids, which are the link between the Pselophytes and more advanced groups of ferns. According to many of their features (appearance and internal structure, etc.), edible plants noticeably differ from other ferns and occupy a rather isolated position in the fern-shaped system. The class is represented by one order (Ophioglossales), which, according to a number of taxonomists, includes only one family of cooper (Ophioglossaceae) and three genera: the hawthorn (Botryhium), the cooper (Ophioglossum) and the helminthostrahys (Helmintostrahys). Many taxonomists hold a different opinion, distinguishing all three genera into separate families (Botryhiaceae, Ophioglossaceae, Helmintostrahyaceae), or the last two are combined into one clove family (Botryhiaceae) with two subfamilies. Clove flower and cooper are very widespread around the globe, and the genus helminthostrachis lives only in the tropical forests of the eastern hemisphere (from India and Taiwan to Northern Australia). The family got its name by the genus Ophioglossum, which is translated from Latin as “snake language”.
Uzhovnikovye - small or very large sizes (from a few centimeters to 4 m) perennial, summer-green or evergreen herbaceous plants growing in forests and in open places. Among the representatives of the order there are also epiphytes (the inhabitant of tropical forests, the cooper hanging O.pendulum with hanging leaves up to 4 m long).
Ozhnovikov stems are short and erect underground underground rhizomes, but helminthostrachis and epiphytic species of the cooper have horizontal rhizomes. The stems are usually simple or sometimes branching, fleshy. The conductive system is an ectoflame siphon wall.
The roots of Ozovnikov are thick and fleshy, usually containing mycorrhizal fungus and devoid of rhizome hairs.
The leaves of Ozhnovikov are peculiar and, unlike the leaves of other modern ferns, do not coagulate at juvenile age, have vaginal stipules, and the petioles at the base have special membranous vaginas covering the kidney. In most uzhnikovyh plants, only one leaf is formed each year, and only in some species up to 4-6 leaves are formed. The leaves of Ozhnikovykh differ in that they are divided into two parts that differ sharply in form and function - the vegetative (sterile) and spore-bearing (fertile) ones. The vegetative and spore-bearing parts of different representatives of the Ozhnovikovy species are distinguished by a wide variety of shapes and structures. Thus, the vegetative parts in clumps are usually multiple-, triple- or pinnately dissected, in epiphytic forms they are often forked or serrate-divided, and very rarely their plate is completely reduced.
The sporophyte of this group of ferns is characterized by the presence of a small vertical (in terrestrial forms) rhizome, usually developing one (less often several) bifid leaf, one part of which photosynthesizes and the other spores, and in the young state the end of the leaf is not coiled.
Sporangia do not have any devices for opening and are torn apart by a gap. They are formed from several cells of the spore-bearing part of the leaf and carry a multilayer wall - a feature that is considered primitive among ferns. Sporangia sores also do not formulate, they are deprived of Hinduism, but sometimes grow together with syningia. The clump is also characterized by a primitive arrangement of sporangia not only on the sides of spore-bearing branches, but also on their tops. In the anatomical structure, it should be noted the absence of a large amount of mechanical tissue in the organs of plants. This group differs from most other ferns by the presence of endotrophic mycorrhiza in the roots of the sporophyte, as well as a symbiotic fungus in the tissues of the gametophyte, without which it cannot develop. The gametophyte of the Ozhnovnikovs leads an underground lifestyle, develops over several years (up to 10 - 20), which is also a primitive sign, and is a worm-like, sometimes weakly branching and more or less tuberous colorless body, rather large, reaching 6 cm in length, and in some species, from 1 to 2 cm in length.
The spore-bearing parts of the representatives of the genus hawthorn are pinnately branched, paniculate, in species of the genus Creeper, they are whole, linear, spike-like, uglintostrachis - feathery, but with shortened lobes, and therefore appear spike-like.
Ozovnikovy sporangia are quite large (with a diameter of 0.5 to 3 mm), contain a large number of spores (from 1500 to 15000 each), have multilayer walls, are located both on the sides of the branches of the spore-bearing part, and on the tops of individual branches, or sporangia are immersed in tissue spore-bearing segment. The sporangia of the Ozovnikovs have no rings and open with two wings. Disputes with technical radiation notebook scar.
The spores of most species germinate only in the dark and only after a more or less prolonged period of dormancy (in some species, the dormant spore is small, and spores germinate quickly, once in suitable conditions). Ozhnovikov's gametophytes are underground, fleshy, pale colored, gray, yellowish and brownish, varied in size and shape. In the early stages of development, the endophytic fungus, which is necessary for the normal growth of the gametophyte, penetrates into the fabric of gametophyte uzhnikova.
Gametophytes numerous and located on the surface of the gametophyte randomly, or in some representatives of anteridia occupy the top of a special crest, and archegonia are scattered along the edges of the crest or on the ventral side of the gametophyte. Antheridiae are large, submerged or slightly protruding above the surface of the gametophyte; Archegonia are rather deeply submerged. Antheridia and archegonia ripen at the same time (the anteridia are the first to mature). After fertilization, several embryos appear on one gametophyte, but only one of them finally ripens.
The embryos in some representatives of the cooper species develop rapidly (within one year), in others slowly, over several years. In the embryo of rapidly developing representatives of the cochlea, the leaf and shoot growth point appear first, then one or two roots. Later, the leaf comes to the surface of the earth and turns green, and the gametophyte soon dies. On the contrary, in slowly developing gametophytes, the roots develop first, and then the first reduced underground sheet appears. Among pozhnikovykh there are species with a relatively low chromosome number (2n = 90), but there are also species with the highest numbers among all vascular plants (2n = 1320).
Many uzovnikovye capable of vegetative propagation. New plants emerge from buds formed on the underground short stolons.
The widows are confined to forest, meadow, tundra, and bog communities, but at the same time they are quite common in marshes with ever-disturbed vegetation (abandoned forest roads, excavations, cattle tracks).
Epiphytic edibles grow not only on trees, but also on the plexuses of the roots of other epiphytic ferns.
There is one order in the class with two families: osovnikovye (Ophioglossaceae) and thorny (Botrychiaceae). The first family contains one genus, and the second includes two genera (Botryhium and Helmintostrachys).
The genus Ochovnik (Ophioglossum) has 40-50 species, combined into three subgenera and distributed both in tropical and partly in temperate regions of the earth.
The order has only one family of Ophioglossaceae, therefore the characteristic order and the characteristic of the family are the same.
The Ophioglossaceae family includes three genera: Ophioglossum — the cooper, Botryhium — the hawthorn, and Helmintostrahys — helminthostrachis. Udovnik and the clump are represented by a few species in the flora of central Russia, and the monotypic genus helminthostrachis is a tropical plant.
For the northern flora, the usual, but growing in “secluded” places, plant is Ophioglossum vulgatum, an ordinary cooper. This is a small plant, 8 to 10 less often up to 30 cm, a plant found in forest edges or clearings, in moist meadows overgrown with mosses. Its terrestrial organs are represented by only one sheet, clad at the base of the vagina. The leaf consists of a rather long petiole, turning into a narrow, unbranched spore-bearing part of the leaf and into a whole oval green photosynthetic part. Under the ground there is a short fleshy, vertically located rhizome with accessory roots extending from it, in the cortical parenchyma of which endotrophic mycorrhiza is contained.
Sporangia, lying in two rows on a narrow spore-bearing light-colored part of the leaf, form two long synangas along the edges of the leaf. They do not have any special devices for opening, but simply they are torn by a transverse slit, spilling out spherical, with a sculpture clearly visible on their surface, spores that retain viability and germinate for a long time in the dark.
The gametophyte of the common gooseberry mycotrophic, worm-shaped, sometimes branching, lives in the earth, in its surface layers. It is devoid of green color, has a fleshy consistency and, in the early stages of ontogenesis, enters into symbiosis with the fungus. The gametophyte is always bisexual, archegonia with anteridia are located on its surface without any order. Archegoniums are quite deeply immersed in the gametophyte tissue, and large anteridia can slightly protrude above its surface. They do not ripen at the same time, the anteridia are the first to ripen, so that the gametophyte, the cooper functions as the same sex, which causes cross fertilization, and sometimes even leads to hybridization between different species.
The development of the embryo proceeds at a slow pace: only a few years after fertilization does the first still underground leaf appear, and the gametophyte, thus, feeds the developing sporophyte for several years. As a result of such a delayed development, both the gametophyte and the sporophyte embryo, many years pass until a sexually mature gametophyte and spore-bearing mature sporophyte emerge from the spore. Such a slow pace of development is a testament to the great antiquity and primitiveness of the edibles.
The genus Ophioglossum has about 50 species, distributed in the temperate and tropical zones. Tropical poopers often lead an epiphytic lifestyle. These are rather large plants, often with strongly dissected hanging leaves, sometimes with numerous spore-bearing parts of leaves, such as in O. palmatum. In epiphytic coopers, rhizomes are more or less horizontal, creeping along the substrate.
The second genus - Botryhium - a bunch of berries, is represented in the temperate zone by several species.All of them are easily distinguished from the cooper by the always cirrus-dissected and twice-thrice-cirrus-dissected vegetative sprouting parts of their leaves. One of the common species of B. lunaria, the crescent, lives in forest glades, edges and lanes in broad-leaved, less often in spruce forests, sometimes also found in moist meadows, usually growing in groups.
In B. lunaria, as in O. vulgatum, which has a fleshy vertical rhizome, from which the adventitious roots depart. The leaf is also one, dressed at the base of the vagina and also divided into spore-bearing and vegetative parts. The vegetating part of the leaf is pinnately divided into semicircular or kidney-shaped lobes, the spore-bearing part is twice or thrice pinnately divided, and its branches are covered with spherical sporangia that are not fused in synanga, as in Ophioglossum. Sporangia, like all uzhnikovye ones, open with a transverse slit, and more or less tetrahedral spores ripen in them, with a surface sculpture clearly visible under a microscope.
Gametophytes Botryhium often have a tuberoid, ovoid form, and for anteridia and archegonia there are zones on the gametophyte: anteridia develop on the top of the gametophyte, sometimes on a protruding crest or ridge, and on the archegonia - on the sides of such a crest.
In such species of river. Botryhium, like B. vulginianum, a virginian hawthorn, or B. multifidum, a hawthorn divisible vegetative part of the leaf is divided more strongly - twice and thrice cirrus.
Most species of the thunderbird are found in the temperate zone; the genus has about 40 species.
The genus Helmintostrahys is monotypic, contains one species H. zeylanica, a typical tropical plant of the Old World. The vegetating part of its leaf is rather dissected, and the spore-bearing part of its leaf is dissected quite strongly, and the spore-bearing does not branch and carries sporangia that are not fused with each other. Like many epiphytic poopers, helminthostrachis is an evergreen plant.
This is the most peculiar and mysterious class of ferns. Their modern representatives in a number of ways differ significantly from typical ferns, and their history is unknown, although it is undoubted that this group is very ancient. The cooper class includes one order of cooper (Ophioglossaceae), one family of cooper (Ophioglossaceae) and 3 genera - cooper (Ophioglossum), greenhouse (Botrichium) and helminthostachis (Helmintostachys).
Shmakov A.I. Systematics of higher spore plants. Part 1. - Barnaul: Alphabet, 2007 .-- 239 p.
Sergiavskaya E.V. Systematics of higher plants. Practical course. 2nd ed., Erased. - SP .: Publishing house "Lan", 2002. - 448 p.
Timonin A.K. Volume 4. Systematics of higher plants. Book 1. - Moscow: Academy, 2009. - 320 p.
Elenevsky A.G. Botany. Systematics of higher spore, or terrestrial plants. 4th ed., Erased. - SP .: Publishing Center "Academy", 2006.-464 p.
The family of ozhnikovye (Ophioglossaceae) (V. R. Filin)
We will begin our acquaintance with the living ferns with the family of coopers. In many of its characteristics, this is a very primitive group, which, in all probability, comes from the oldest Paleozoic ferns. Unfortunately, the geological history of the Ukhovnikovs is unknown to us. In appearance, internal structure, as well as in some of their important biological features, edible plants noticeably differ from other ferns and, thus, occupy a rather isolated position.
There are only 3 genera in the family of ozhnikovs: moonwort (Botrychium), supper (Ophioglossum) and helminthostachis, or wormworm (Helminthostachys).
The thunderbird and the cooper are very widespread throughout the globe, while species of the first kind are mostly found in the northern temperate zone, and most species of the second are tropical. The only species of helminthostachis lives in the tropical forests of the eastern hemisphere - from Sri Lanka and India to Taiwan, New Caledonia and Northern Australia.
The family received its name by the genus Ophioglossum, which is translated from Latin as "snake language." Russian names - "pagan", "serpentine" or "snake" also indicate the characteristic appearance of one of the species of this genus common in Europe - common supper (O. vulgatum).
Fig. 95. Uzovnikovye: 1 - Ceylon helminthostachis (Helminthostachys zeylanica): a - part of the sporophyll with a ternary dissected sterile segment and with a spike-shaped spore-bearing segment, b - spore-bearing sprig with sporangia and leaf-shaped appendages, 2 - Oryngum palmatum (Ophi pal general view of the plant, d - plot of the spore-bearing segment with sporangia immersed in its tissue, 3 - common cooper (O. vulgatum), 4 - multi-branching bunch (Botrychium multifidum): e - general view of the plant with overwintered, sterile segment and sporophyll of the current year , - Sporebearing segment portion sporophylls
Ouzhovnikovye - small or medium sized perennial, sometimes evergreen grasses growing on loose and moist soil in forests and in open places, but some tropical species of uovnik are epiphytes.
The largest representative of the family is tropical epiphytic hangman (O. pendulum, tab. 18), with hanging leaves about 1.5 m long, and sometimes up to 4 m. The smallest representatives of the family are invisible plantlets several centimeters high, with very short rhizomes.
Ochovnikov stems for the most part are short and erect underground rhizomes. Horizontal rhizomes are found only in helminthostachis and in epiphytic species of cooper. The stems are usually simple, sometimes branching is observed, which occurs, as a rule, as a result of the awakening of sleeping lateral buds.
Ochovnikov stems, like their leaves, are soft and usually somewhat fleshy, without mechanical tissue characteristic of most modern ferns.
The conduction system of the stem is an ectoflame siphon-stela or, as in most species of an ovary, a dictostele. At the same time, the xylem is endarchic in the cluster and pooper, which is rather unusual for ferns (but in the helminthostachis, the xylem is mesarchic). Metaxilema tracheids are staircase or with oval or rounded bordered pores.
The roots of Ozovnikov are thick and fleshy, in many species retracting. The cells of the root cortex usually contain mycorrhizal fungus, which belongs to phycomycetes. These mycorrhizal roots are devoid of root hairs.
Very peculiar leaves of Uzovnikovye. They differ from the leaves of almost all other modern ferns (with the exception of the Salvinia ferns) in the absence of cochlear (spiral) twisting in budding, although coarse bud rudiments can be found in the kidneys in powerful specimens of some species of bunch.
Another characteristic feature of the leaves of the plant is the presence of special vaginas covering the kidney. In most uzhnovikovyh trees, only one leaf is formed each year (in some small-leaved species of uzhnikov - 4-6), and therefore the age of the plant can be roughly estimated by the number of leaf scars on the rhizome. Estimates show that some plants common in our country, especially in pine trees, multi-branching (B. multifidum) are the same age as many centuries-old pine trees living in the neighborhood.
The slow growth of leaves is one of the characteristic features of the scrub, distinguishing them from many modern ferns. Each unfolding leaf makes its way through the vagina of the preceding leaf. Moreover, leaves come to the surface only in the fourth or even fifth year of their development.
The leaves of Ozhnikovykh are also characteristic in that they are forks divided into two parts that differ sharply in form and function - the vegetative (sterile) and spore-bearing (fertile) ones. Both vegetative and spore-bearing parts (segments) in different representatives
Uzhovnikovs are distinguished by a wide variety of shapes and structures. The vegetative segments of the cluster are repeatedly, triple, or pinnately dissected, rarely (in some of the smallest forms) whole. In helminthostachis, they are many times dissected, while in the cooper it is usually whole or lobed, but in epiphytic forms it is often forked or (in fingertip - Ophioglossum palmatum) palmate-separated. The reduction of the vegetative part of the leaf has reached extreme limits in the Japanese species Kovamura's supper (O. kawamnurae), where this part of the leaf has almost completely disappeared.
Fig. 96. Uzhovnikovyh: at the top - a virginian hawthorn (Botrychium virginianum), below - a lunar hawthorn, or a grass key (B. lunaria)
In close connection with the reduction and simplification of the vegetative segments, the same simplification of the spore-bearing parts occurred. Spore-bearing segments in the genus Clover are pinnately branched, paniculate, in helminthostachis they are also cirrus, but with shortened lobes and therefore spike-like, in the genus Udovnik they are whole, linear. Very interesting is the tropical palm fringe, characterized by a plurality of spore-bearing segments.
The spore-bearing segments of the cooper species carry sporangia, the arrangement of which is very different in different genera. The most primitive type of arrangement of sporangia is observed in the hawthorn. Its sporangia are located both on the sides of the branches of the spore-bearing part, and on the tops of individual branches. A conductive bunch approaches the base of each sporangium, which is considered as a primitive attribute that is not characteristic of other modern ferns. The sporangia of the cooper is completely different. A conductive bundle is also suitable for each of its sporangia, but the sporangia themselves are immersed in the tissue of the spore-bearing segment or form two long synangas along its edges.
Ozhorovnikov sporangia are quite large (with a diameter of 0.5 to 3 mm), contain a large number of spores (from 1500 to 15 000 each) and have massive, multi-layer walls. In the early stages of its development, sporangia are very similar to sterile segments and even the top of the stem, this similarity is increased due to the presence of stomata on the legs and side walls of sporangia.
The sporangia of the Ozovnikovs have no rings and open with two wings. Disputes with a three-beam notebook scar. All three genera of the family are well distinguished by the nature of the surface of the spores.
Fig. 97. Odzovnikov disputes: at the top - the spore of the common cooper (Ophioglossum vulgatum) (stolen, about 1500), in the middle - the spore of the crescent lunar (Botrychium lunaria) (stolen, about 1450), at the bottom - the spore of helminthostachis ceylon (Helminthostachys zeylanica) c. 1650)
The spores of most species germinate only in the dark and only after a more or less long period of dormancy, having a strong shell, they retain their viability for a long time. When rain falls, snow melts, as a result of the digging activity of various animals and just when the plant litter accumulates, the spores sink into the soil, where some of them sprout. In some species, the dormancy period is short, and the spores germinate quickly when they are in suitable conditions.
Ochovnikov gametophytes are white, underground, fleshy, pale colored, gray, yellowish or brownish. Already in the early stages of the gametophyte gametophyte development, an endophytic fungus penetrates into its tissue, which is necessary for the normal growth of the gametophyte. The number of gametophytes of Ozhnovikov found in the surface soil layers in the places where sporophytes grow is sometimes very large (tens and hundreds of specimens on an area of 10 dm 2). But in some species, gametophytes, despite careful searches, have not yet been found.
Gametophytes of Ozhnovikov are diverse in size and shape. Probably the most primitive can be considered cylindrical, weakly branching, vertical gametophytes of some species of cooper, for example, common cooper. Such gametophytes grow using the apical meristem, mature in 10-20 years, reaching a length of 6 cm with a diameter of about 1 mm. Gametophyte branches, coming to the surface of the soil, can turn green. From cylindrical gametophytes in the course of evolution, tuberous, gametophytes ripening during the year could occur rattle (O. crotalophoroides) and highly branched gametophytes of palm tree, living in humus on the trunks of tropical trees.
Fig. 98. Overgrowths (gametophytes) and seedlings of the cooper: 1 - a sprout of the common cooper (Ophioglossum vulgatum), 2 - a overgrowth with the root of the germ (c) of the common cooper, 3 - overgrowth of the rattle coot (O. crotalophoroides), 4, 5 (O. pendulum), 6 - a sprig of palmate cooper (O. palmatum), 7 - a sprout with embryos (h) of a blackhawk, 8 - a sprout of a Virginian stem (Botrychium virginianum) with an anteridial crest (d) on the upper side, 9 - transverse a section of a virginianus clump overgrowth, cells with fungal hyphae are visible in the lower part of the overgrowth, on the upper side of the seedling, two anteridia are visible on the left, three archegoniums on the right, 10 - a Virginia clump with a young sporophyte attached to it, 11 - a seedling of helminthostachis zeylanica (Helminthostachys zeylanica)
Gametophytes of helminthostachis are short, lobed in the lower part, and cylindrical in the upper, bearing gametangia. The gametophytes of the cluster are dorsiventral, ovate, flattened tuberous or discoid, 1 to 20 mm long.
The gametangia are numerous and scattered on the surface of the gametophyte, either without any order or (at the clump) anteridia occupy the top of a special crest, and archegonias are scattered along the crest slopes or the ventral side of the gametophyte. Antheridiae are large, submerged or slightly protruding above the surface of the gametophyte; Archegonia are rather deeply submerged.
Like many equidistant ferns, anteridia and archegonia on the same gametophyte ripen at the same time: the anteridia are the first to ripen. This contributes to cross fertilization and, in some cases, hybridization of closely related species. After fertilization, several embryos may arise on one gametophyte, but only one of them finally ripens.
The genera, and often the subgenus, are different among themselves in the type of embryogenesis, the form and rate of development of the embryo. For example, a rattle rattle with neotenic tuberous gametophytes is also characterized by the accelerated development of the embryo, which ripens during the year. The leaf and shoot growth point appear first at the embryo, then one or two roots. The leaf comes to the surface of the earth and turns green, and the gametophyte soon dies. On the contrary, on the slowly ripening cylindrical gametophyte of the common cooper, the embryo develops slowly: it takes several years after fertilization before the first reduced underground sheet appears at the embryo following the roots. In some ozhnovikovs, perennial gametophytes have long been “feeding” sporophytes, which already have green leaves.
Among pozhnovikovyh there are species with a relatively low chromosome number (2n - 90), as well as representatives with very high numbers. At nether (O. reticulatum) there are 2n = 1260, while large-sized supper (O. pycnostichum) - even 2n = 1320 (the highest number of chromosomes among living plants). Famous american nerd L. Stebbins in his book "Chromosomal Evolution in Higher Plants" (1971) writes: "It borders on a miracle." that so many chromosomes can find each other during meiosis during the formation of hundreds of bivalents (connected by pairs of homologous chromosomes) in each sporocyte. Cytologists consider 15 to be the main number of chromosomes (x) in species of this family.
Many coopers have the ability to efficient vegetative propagation. New shoots appear from the buds formed on the roots.
Usually associated with forest, meadow, tundra, and bog communities, many uzhnikovye communities are often found in places with once disturbed vegetation cover (overgrown roadsides of forest roads, excavations, etc.). Different species grow on soils of different composition and acidity.Epiphytic edibles often settle on the plexuses of the roots of other epiphytic ferns (platycerium - Platycerium, asplenium nest - Asplenium nidus) and inhibit the "host" (tab.18).
All uzhnikovye are obligate (obligatory) mycotrophs, but the degree of dependence on mycorrhiza is different in different species. Without root hairs and a deep root system, as well as special devices for the rapid absorption of water and reduce its return, widows in dry periods are largely dependent on the moisture content of the substrate.
Helminthostachis and epiphytic coopers are evergreens, but the maximum formation of new leaves and the sporulation period in them occur at a certain time of the year. The ground-borne moths of the temperate zone have summer-green leaves, dying off in winter, but if summer and autumn are warm and humid, then in autumn plants can give a second generation of leaves. There are summer-green species within the genus Clover (for example, lunar hawthorn - Botrychium lunaria and virginian hawthorn - V. virginianum) and "winter green" species (for example, the hawthorn is divided). In the latter, the leaves unfold in the summer and after sporulation, which usually begins in late summer - early autumn, the fertile segment dies, and the sterile hibernates and remains until the next year by the time the new leaf unfolds. Common in the southeastern United States moon-shaped hawthorn (B. lunarioides) - a real winter-green plant: leaves from it begin to appear in October and die by May.
Some species are associated with various beliefs. The lunar creeper is called the grass key because of its supposedly inherent ability to help locate treasures. The United States Virgin Horticulture is called a pointer, as it supposedly indicates the location of dwarf ginseng - the three-leafed Panax (Panax trifolius) - the American cousin of the famous ginseng. And although the widows have no economic value, this peculiar and small group deserves a careful attitude to themselves, and many species have long been in need of protection.