This order, which sometimes is called Isobryales, is sometimes included into the Bryales because of characteristics of the peristome, and sometimes it in included into the Orthotrichales.
But the members of this order differ in their habit clearly from plants of those two groups. They are pleurocarpous mosses with creeping principal stems and ascending or pending branches. The capsules sit on short side branches, and the seta sometimes is very short.
The order contains a number of smaller families: Fontinalaceae, Hydropogonaceae, Cryphaeaceae, Leucodontaceae, Neckeraceae, Racopilaceae, Thamnobryaceae (Thamniaceae), Hypopterygiaceae, Climaciaceae, Phyllogoniaceae, Pterobryaceae and Meteoriaceae. Some tropical families I certainly forgot.
This family consists of water mosses. Some species can stand temporary dryness, but most species are living always under water. The plants are rather big, in most cases 20-30cm long.
The apical cell, with which mosses grow, maintains its position during growth. As a consequence the mosses of this family are clearly triseriate (leaves are in three rows). (Some species have 5 rows, as far as I know.)
The leaves of the plants of this family are acute ovoid until lanceolate. In most cases they are sharply keeled and hollow. A midrib may exist or not. The edge of the leaf is smooth or at most serrulate at the tip. The cells are prosenchymtic. Many species only very rarely form sporogonia. Normally they reproduce vegetatively with broken shoots.
The family consists of 6 genera in the regions with moderate or cooler climate of the northern hemisphere. In Europe the genus Fontinalis with about 6 species, and the genus Dichelyma with two species can be found. The latter seemed to be extinct in Germany at the beginning of the 20th. century, but was found again 1996. The Fontinalis plants are getting rarer, because they need natural, clean water.
These are in most cases mosses, which grow on bark. The principal stems are creeping on the substrate, the branches are erect and are unramified until pinnate.
The leaves are acute, hollow, and with a midrib. The cells in the upper part of the leaf are rounded, in the lower part they are elongated. The capsules are immersed into the leaves, and the calyptra is small and campanulate (bell-shaped).
The familiy consists of 11 genera in regions with moderate or warmer climate. In Europe it is represented by only 2 species. The species Alsia abietina was used as packing material for vegetables in California.
The family Leucodontaceae consists of 9 genera in regions with moderate or warmer climate. They are in most cases more or less robust plants, which grow on bark or rock. The principal stems of the plants are creeping. The branches are only little ramified, erect or often pendant.
The leaves are in most cases ovoid or ovoid lanceolate. There are species with simple midrib, without midrib, with a short double midrib, or with several side ribs. The cells in the upper part of the leaf normally are rhombic, in the lower part elongated, the alar cells sometimes quadratic.
None of the species is frequent in central Europe. The most frequent species is Leucodon sciuroides, which can sometimes be found in the mountains, and which is shown on the drawing on the right, too.
Under all families of the order the name giving Neckeraceae are very easily to recognize by its flattened stems: Although the leaves sit in spirals on the stem, the leaves on the upperside and the underside are appressed, and the leaves at the sides are turned in such a way, that all leaves are in plane orthogonal to the light. Such a flattened stem can be seen on the drawing on the right (which shows Neckera complanata).
The cells of the blade are short oval until long oval, but in every case smooth (not papillose). A midrib may exist or not.
The members of this family in most cases form robust, ramified and very glossy turfs. In total there are 11 genera, of which three can be found in Europe, and two in Germany.
Also the plants of this family are normally flattened. In contrary to the Neckeraceae the leaves on the sides of the stems, and the leaves on the upperside are different: The side leaves are oblique, dense and asymmetrical. The leaves on the upperside are symmetrical and distant one from another.
The mosses of this family have a noticeable treelike habit: The principal axis creeps. From it stems ascend. The axis and the lower, unramified part of the stems only have reduced, scalelike leaves.
The leaves on the upper branches are lanceolate, with a midrib, and coarsly serrate. The midrib ends in most cases in the tip of the leaf. The cells of the leaves are round.
I don't know the number of genera and the range of this family. In Europe it is represented only by the genus Thamnobryum with three species. On Madeira and the Canaries there is at least one more species. Also the drawing on the right shows a member of this genus: Thamnobryum alopecurum.
Similar to the plants of the Thamnobryaceae and the Climaciaceae those of this family have a creeping axis, of which treelike stems ascend. The axis and the lower part of the stems are covered only by little scalelike leaves. The arrangement of the leaves at the upper part is complicated: In total the stems are flattened. At each side there is a row of large, widespreading leaves, but there are also smaller underleaves similar as in Selaginella.
The leaves always have a midrib. They are limbate (bordered by elongated marginal cells) and the cells are round.
The familiy has its center of diversity in Malaysia and Australasia, but can be found allover the tropics. One species from Australia and Oceania seems to be imported into greenhouses and was very rarely found at the outside in Portugal. It is a small familiy with about 7 genera, of which 160 species are described. But many species seem to be described several times. A recent monography count 21 species (Hans Kruijer - Hypopterygiaceae of the World; Published by The National Herbarium of the Netherlands; Monograph, 2002; 388 pp., with line drawings and distribution maps ISBN 90-71236-51-X).
This family consist only of the name giving genus Climacium with four species in total. These are characterised by rhizome like creeping main stems, and robust, treelike branches.
Further information can be found in the file about the only central european species Climacium dendroides, which is shown on the drawing on the right too.
About this familiy I don't know anything, except that it contains the species Myurium hochstetteri, which can be found on Madeira and the Canaries, and very rarely on the west coast of Ireland and Scotland.
This is a numerous tropical family, whose members grow mainly pendant from bark. In Europe there is only one species, which was found near vulcanic steam fountains on the Liparic Islands (near Sicilia).