Moss Classification

Mosses belong to the phylum Bryophyta in the classification now commonly used, or in other classifications they are made a division of the Archegoniatae which, in distinction from the Thallophyta, are plants that exhibit a true alternation of generations in their life history. As is true with ferns, they possess antheridia in which the spermatozoids, or male gametes, are produced and archegonia (flask-shaped structures with a single-cell layer in their walls) in which the eggs, or female gametes are produced. They are the highest of the non-vascular cryptogams, lacking a true conducting system, although having a differentiation into stem and leaves. They do not possess true roots, but rhizoids.

The phylum Bryophyta is divided into two classes - the class Hepaticae of the Liverworts, and the class Musci, or the mosses. Of these two classes the Hepaticae have a poorly developed protonema of the sexual generations and the gametophyte, when developed, is either a branched thallus or a leafy (usually dorsiventral) shoot. Most of the Hepaticae have elaters or sterile cells which, during the growth of the sporogenous tissue, serve to help conduct nourishment to this tissue; later those cells aid, by their hygroscopic behaviour, in scattering the spores. Only one order of the Hepaticae (the Anthocerotales) have a columella, or central axis, of sterile cells of the sporangium. The class Musci always have a well developed protonema, and the gametophyte is a leafy shoot with the leaves spirally arranged, rarely in two rows. The moss capsule never possesses elaters and, except in one genus, always has a columella.

The classification of the North American mosses used, is essentially that of A. J. Grout in his "Mosses with a Hand Lens and Microscope" and "Moss Flora of North America". It is also similar to that of Dixon & Jameson's "The Student's Handbook of British Mosses".

CLASS MUSCI

Order I - Sphagnales

Family 1. Sphagnaceae - The Peat Mosses.

Order II - Andreaeales - The Rock Mosses.

Family 2. Andreaeaceae

Order III - Bryales - The higher mosses.

This order is divided into two suborders:

Suborder 1. The Nematodonteae,

consisting of three families, the distinguishing character of the group being solid peristome teeth.

Family 3. Buxbaumiaceae
Family 4. Tetraphidaceae
Family 5. Polytrichaceae

Suborder 2. Arthrodonteae,

consisting of two groups. The distinguishing character of the suborder is the jointed nature of the peristome teeth.

(Group 1. Aplolepideae.)

The distinguishing character of the group is the single peristome, consisting of two rows of colored cell-plates formed by a deposit on the inside and outside of the original cell wall of the sporogonium. Teeth are usually sixteen in number and may be entire or cleft to the base, making thirty-two teeth.

(Group 2, Diplolepideae.)

The distinguishing character of this group is the normally double peristome. This consists of an outer peristome which is composed of jointed teeth in two rows; the inner peristome, on the other hand, is composed of thin and membraneous tissue. The outer peristome consists normally of 16 teeth; the inner of 16 segments alternating with the teeth of the outer peristome and united at their bases into a continuous membrane. Philibert's researches show that the single peristome of the Aplolepideae is homologous to the inner and not the outer peristome of the Diplolepideae.

(Subgroup 1. Diplolepideae Acrocarpae.)

These are the diplolepideae which bear the sporophytes terminally. The plants are erect, rarely prostrate, and the branching is dichotomous.

(Subgroup 2. Diplolepideae Pleurocarpae.)

These are the diplolepideae which bear the sporophytes on a lateral bud on the side of the main stem or branches. The plants are usually prostrate, occasionally erect and the branching is often pinnate or subpinnate, seldom dichotomous.

A short description of each of these families follows with a brief account of their importance and their geographical distribution.

Order 1. - Sphagnales

Family 1. Sphagnaceae - The Peat Mosses

Known throughout the world to the layman as peat mosses, this family which consists of a single genus, Sphagnum, composes the basis of bog vegetation in central and higher latitudes where it often forms a pure Sphag num formation. Morphologically, they differ from the rest of the mosses not only vegetatively but also in the structure of the reproductive organs According to the latest works, there are 336 species in the world of which 35 species are confined to North America. The mosses will grow to lengths of several feet with the bottom continually drying and slowly decaying thus forming a black mass which in its incomplete or impure state is known as muck. The property of holding moisture is most important so that peat is used for packing flowers and bulbs and also for litter.

These are among the most easily recognized mosses for the beginner. They are always found in wet places and are a grey-green color with the tip of the plant sometimes reddish or pinkish. For convenience in classifying, they are divided into the Spoon-leaved and the Acute-leaved Peat Mosses. They occur in a number of places in Mount Rainier National Park and at a number of elevations where past glacial action has resulted in poor drainage.

Order II. Andreaeales

Family 2. Andreaeaceae -- The Rock Mosses

A small family of mosses consisting of only two genera, of which one, Andreaea, occurs in North America. The generic name is derived from the name of an apothecary of Hanover.

These mosses are not lime-tolerant, hence the are confined to granitic or slaty rocks and are strictly alpine or subalpine in their distribution. They grow on rocks where they form dark-green or olive-green tufts, sometimes almost black in color. This plant is interesting here on the mountain in that it exhibits remarkable color changes as a result of strong lighting, changing to yellow brown and even to dark red as the protective pigments develop. In addition to color changes, these plants show remarkable changes in leaf shape and cell forms. Many species are thickly leaved with catkin-shaped shoots and others have thin, wiry leaves.

Order III. Bryales

Suborder 1. Nematodonteae.

Family 3. Buxbaumiaceae.

A family of a single genus, Buxbaumia (name derived from Buxbaum, a German botanist). The leaves are tiny and sparse being clustered at the base of the seta. These leaves disappear when the capsule matures so that the plant then consists of a roughened seta at the top of which is perched the queer, flattened, bug-like capsule. One species, which is very common on rotten logs in the deep Douglas fir forests about Longmire, has been found; this species is Buxbaumia Piperi.

One of the interesting features of the family is the peristome which is intermediate between the Nematodonteae and the Arthrodonteae.

Family 4. Tetraphidaceae.

This family was formerly known as the Georgiaceae, a name applied as an act of respect to King George III of England when the botanists were under royal patronage. This is one of the most easily recognized of the moss families since all of the mosses belonging here have a peristome of four long teeth.

A single genus, Tetraphis (Georgia) occurs in North America. The plants avoid calcium and are distinctly northern in their range. Tetraphis pellucida, our representative of the family on Mount Rainier, is pan-boreal. It is found on damp shaded rocks, rotten tree trunks and on peaty soil, which latter habitat suggests a tendency towards saprophytism.

Family 5. Polytrichaceae, The Hair-Cap Mosses.

A very old type of which Polytrichum, Pogonatum and Atrichum (Catharinea) are widely spread over the world. Polytrichum commune, P. juniperinum, P. alpinum and Pogonatum urnigerum are inhabitants of cooler climates. The high bogs may sometimes consist of pure Polytrichetum (Polytrichum juniperinum and P. piliferum). Likewise Polytrichum juniperinum may form a sub-formation, as at Longmire springs, in moist mountain forests making carpets of heavy growth.

The family includes over 200 species and is related closely to the Mniaceae. The distinguishing character is the peristome of 32 or 64 solid teeth. The plants are dioecious with the typical rosettes characterizing the male plants. These rosettes are responsible for the name "moss flowers" which is often applied to them.

Suborder 2. Arthrodonteae.

(Group 1. Aplolepideae.)

Family 6. Fissidentaceae.

The name of the family is derived from "fiss" - split and "dens" - tooth, referring to the split teeth. A large group which is distributed over the entire world with a principal genus, Fissidens, having alone over 700 species. It is one of the most easily recognized mosses having the leaves arranged in two rows. The sporophyte is lateral or terminal and is very similar in appearance to that of the Dicranums. There is one other North American genus, Bryoxiphinus, the Sword Moss, which is found on sandstone cliffs in the Ohio valley. Fissidens is aquatic or subaquatic, or else grows on moist soils or stones.

Family 7. Leucobryaceae

With the exception of Leucobryum glaucum which is distributed throughout the northern hemisphere, this family is tropical, including many tropical epiphytes. The mosses are a pale glaucous green in color becoming white and brittle when dry, hence the name which means "white mosses".

Family 8. Dicranaceae, (Bird-bill Mosses).

The plants of this immense family vary in size from minute forms to very tall and dichotomously branched mosses. Recently considerable revision of the family has occurred so that many of the mosses which were formerly placed under the genus Dicranum have now been placed in the genus, Arctoa.

The usual habitat of the members of the group is on soil or rocks although they are found on trees and rarely on decayed wood. Because of the characteristic appearance of the capsule when the calyptra is still attached, the mosses are often popularly referred to as the "Bird-bill Mosses". The peristome teeth are broad at the base, transversely barred, and forked above. Dicranum scoparium is very widely distributed and in forest associations Dicranum undulatum occurs on drier soils.

On Mount Rainier the Dicranaceae are perhaps more widely distributed than any other group through the life zones at the various elevations on the mountain with a great variation in size between the robust Dicranum fuscescens of the dense Canadian zone forests and the tiny Arctoa falcata of the Hudsonian meadows.

Family 9. Calymperaceae.

So far no representatives of this family have been found on Mount Rainier. It is a small family consisting of only two genera, Calymperes, and Syrrhopodon. The plants are minute to large and form tufts on trunks or stumps of trees. Dixon's Handbook of British Mosses describes the genus, Campylopus, under the Dicranaceae.

Family 10. Ditrichaceae.

This family consist of small plants mostly less than two centimeters in height which grow densely matted together with radicles. The stems branch and the leaves are various. The three most important genera of the group are Ditrichum, Ceratodon, and Distichum. On Mount Rainier Ceratodon purpureus, known as the Purple Horn Cap Moss, is perhaps as widely distributed throughout the various life zones of the Park as any other moss and shows plainly the effect of environment on size. Specimens found at lower elevations will be four or five times the height of the high forms.

Family 11. Seligeraceae.

The name of the family is obtained from Seliger, a Silesian pastor and bryologist. The plants are also small, mostly less than one centimeter in height and grow in dense mats. They are practically confined to the cooler regions with Blindia finding its center of distribution in Antarctica. They frequent limestone where they often are to be detected only by a faint brownish or greenish stain on the rocks. Blindia acuta, the largest species of the genus, grows on wet rocks and ledges at high elevations but so far has not been collected in the park.

Family 12. Archidaceae.

Consists of small perennial mosses growing on the ground in meadows and bare places, usually in siliceous sand. The branches are erect and slender, bearing rudimentary leaves below. The calyptra are small and break irregularly. The spores are few in number, polyhedral in shape and the largest in size of any moss known. The family is small consisting of a single genus, Archidium, and 19 species of which 6 are North American. This genus has its largest distribution in oceanic climates.

Family 13. Grimmiaceae.

Nearly all of the Grimmiaceae are rock mosses, only a few Rhacemitriums being found on humus or sandy soil and none are epiphytes. Scouleria, of the subfamily Scoulerieae, is distinctly aquatic in habit, having been found on rocks near and under water along the Ohanapecosh river.

The members of the group avoid lime and some are silica constant; as such among the rock plants of the young mountains they play an important role in disintegrating the rock.

Most Grimmiaceae, being strongly lighted because of their habitat, form thick mats and develop transparent tips to the leaves which apparently serve to reflect the rays of light. Only a few species are with out this protective medium. Dark colors, due to the protective pigments, are also the common thing. Because of the difficult life conditions, spore development is slow so that sometimes almost two years are required, for example, in Grimmia. In all seventeen species and varieties of this family have been found in the park with the majority of them occurring above elevations of 4500 feet.

Family 14. Tortulaceae, The Twisted Mosses.

These are low-growing mosses with short stems which are radiculose at the base only. They are found mainly on soil but also on stones and the roots of trees. The seta is straight and the calyptra cucullate and smooth. The peristome when present consists of sixteen spirally twisted teeth which are often divided making the peristome appear to be composed of 32 teeth. The family shows relationships to the Ditrichaceae through the genus Ceratodon; to the Funariaceae; and to Encalypta.

Family 15. Encalyptaceae, (Extinguisher Mosses.)

This family consisting of a single genus, Encalypta, is composed entirely of high altitude mosses. They occur in the high altitudes of the tropics as well as in the arctic regions. They are terrestrial or rupestral forms, usually growing in tufts. All of the specimens found on Mount Rainier are rock forms, one collection being made at 7300 feet elevation on Fremont Peak.

A very easy group of mosses for the beginner to recognize because of the large calyptra which enclose the whole capsule and are campanulate or cucullate. The large size of the calyptra is responsible for the name.

(Group 2. Diplolepideae.)

(Subgroup 1. Diplolepideae Acrocarpae.)

Family 16. Erpodiaceae.

A small family of only three genera of which most of the species are tropical in their range. Because of their small size, the Erpodiaceae never build formations but usually grow sparsely on the trunks of trees.

Family 17. Orthotrichaceae.

In this large family the pronounced tendency towards epiphytism is especially noteworthy. Growing on tree trunks at the lower elevations as on the lower slopes of the mountain, we find that as we ascend the mountain the members of the group have a tendency to cover rocks instead.

The mosses of this family form short dense cushions with the stems dichotomously branched. The seta is erect with the capsule exserted or more frequently immersed. Forty-two species of the genus Orthotrichum have been named in North America with O. anomalum a type.

Family 18. Schistostegaceae, (Luminous Mosses.)

A small family consisting of a single genus, Schistostega. The plants are small, reaching only about 10 millimeters in height and grow from a persistent protonema which bears subspherical reflecting cells at the tips. These cells cause the plant to give off a golden-green glow in caves where they live. Schistostega pennata occurs all the way across the continent from the mountains of New England to British Columbia.

Family 19. Splachnaceae.

This group was described by Brotherus as turf-forming bog and mountain mosses living chiefly on earth which is rich in humus or on vegetable or animal remains. In the north they grow usually in the damp forests at high altitudes. While I have not as yet been able to locate a Splachnum in the park, I understand that the plant has been collected in the Carbon river canyon.

The name of the group is derived from the Greek meaning "viscera" undoubtedly because of the wrinkled or rugose appearance of the dry apophysis. The plants are apparently confined to animal carcasses or dung for the founding of a colony. The leaves have large thin-waled cells and become soft and flaccid when dry. The wide apophysis, generally of a different color than the capsule, is sometimes mistaken for the capsule itself. In Splachnum the apophysis is so bright colored that it undoubtedly attracts insects as does the odor of carrion which is exuded by Tetraplodon which attracts flies thus aiding in spore dissemination. The peristome is strongly hygroscopic and consists of 16 teeth. The genus Splachnum is circumboreal in its distribution.

Family 20. Ephemeraceae.

Composed of minute, annual, terrestrial plants which develop on a persistent protonema. In fact the protonema is often the only means of finding the plants which are best sought by looking for bright green patches on the soil.

Dixon in his Handbook of British Mosses mentions that while the protonema may be a storehouse of moisture, they are probably important in crowding out other plants in the battle for supremacy in an area. The two North American genera are Ephemerum and Nanomitrium.

Family 21. Funariaceae.

This family embraces a few small genera which geographically have narrow boundaries. The plants usually occupy areas which are subject to change such as roadsides and stream banks.

Members of this family resemble the Splachnaceae in leaf structure but differ in the fact that the capsule is cernuous. There are five North American genera. The best known member found locally is Funaria hygrometrica, which is known as the Twisted Cord Moss because of the twisted nature of the seta. This moss is abundant in burnt over areas in which it may be found among charcoal.

Family 22. Disceliaceae.

A small family of a single genus and species, Discelium nudum, closely related to the Funariaceae. The moss is gregarious and reproduces by means of a persistent protonema and brood bodies. This protonema dries up soon after the snows disappear and is therefore very difficult to find.

Family 23. Meeseaceae.

Of this family, two monotypic genera, Paludella and Amblyodon, are arctic-alpine in their habitat. The former is found particularly in habiting moraines and similar substrata. Most of the Meeseaceae are found in wet, boggy places often associated with Sphagnum. The genus, Meesea, which characterizes the family, was named after David Meese, a Dutch gardener. The seta are very long and slender and the capsules are curved and pyriform, frequently striated when dry.

Family 24. Aulacomniaceae.

A family which is intermediate between the Bartramiaceae and the Mniaceae and also has characteristics of the Meeseaceae. There are two genera. of which only one, Aulacomnium, frequents North America. Aulacomnium androgynum, which is the North American type species is common about the bases of trees in the lower elevation of the park such as on the Trail of the Shadows near Longmire. It also occurs on earth, fissures of rock and rotten wood.

Aulacomnium palustre is one of the most common bog mosses of the northern hemisphere and one of the most commonly encountered mosses in the moist arctic tundra. A. androgynum is also commonly marked by the presence of numerous pseudopodia which bear minute balls of gemma. By this means the plant is reproduced asexually.

Family 25. Timmiaceae.

A group which through the genus, Timmia, shows a marked resemblance to Polytrichum but by its capsule seems to be related to Bryum. Mosses of this family are northern in their range. There is one genus, Timmia, in North America which has four species.

Timmiaceae grow in tall, robust tufts on soil and rocks or rock detritus. Timmia austriaca, which is found in Mount Rainier National Park represents a true arctic-alpine element. The genus name is derived from Timm, a botanist of Mecklenburg.

Family 26. Bartramiaceae.

The Bartramiaceae are a very large family which through leaf structure, capsule form and size are definitely marked. Another interesting feature of the group is found in the germination pores with which the spores are provided. The mosses are tufted, usually tall and robust, with the stems often producing whorled innovations beneath the flowers.

One of the most outstanding characteristics is the capsule which is globular or nearly so, suberect or pendent. When young, the capsule is bright glaucous green, later becoming brown and often deeply ridged. The peristome is commonly double with the outer peristome of 16 teeth and the inner of 64 cilia. The name of the family is obtained from Bartram, an American botanist.

These mosses are quite conspicuous elements of the moss flora in the park being found on moist canyon walls and in the wet places of the Hudsonian meadows.

Family 27. Bryaceae.

By far the great majority of these mosses are earth forms although a few occupy rocks. Many of the genera are important bog forms. Usually they are found on bare earth or sandy places and as such find many favorite habitats above timberline; a few are found near the water.

The Mniaceae is the most closely related family although neither is derived from the other. Dr. Andrews points out that many workers have attempted to keep a single genus, Bryum, with many species (possibly aggregating as many as 500 in the entire world) but in the Moss Flora of North America North of Mexico Volume II, Part 3, he makes two sections or groups of genera. These are the Pohlioidcae and the Bryoideae, of which the former are considered the more primitive.

The Bryaceae are small to large conspicuous mosses growing in loose tufts or loosely aggregated or scattered. The setae are strong end the capsules are typicaly pendent, sometimes horizontal or inclined, seldom erect. The peristome is normally double and complete. The family is well represented in the park and members have a wide altitude range. A member of this group, Pohlia Wahlenbergii, was collected on two occasions inside the crater at the summit of Mount Rainier.

Family 28. Mniaceae.

Fine mosses and probably the most easily, recognized of all the moss families by the broad, shining and translucent leaves and the characteristic Mnium capsule (See Plate XIV, Figs. 1 and 2). In all about 100 species are included in the family. Bogs, woodlands and shady moist areas are inhabited. The northern hemisphere is particularly rich in the cooler moist regions.

Lindberg separated the genus, Rhizogonium, into several genera as R. Microphyllum to Trachycystis, R. acanthoneuron to Leucolepis, etc. The leaves of the group have been mentioned as an important identification characteristic. The capsule is on a long rigid seta, pendent or horizontal, differing from that of Bryum in that it is more cylindrical.

The Mniaceae are common in the moist forests which clothe the base of Mount Rainier and afford an ideal habitat for the group. Technically they are classified as microthermic to mesothermic hygrophiles. By far the most striking members are Roellia and Leucolepis (recently changed to Mnium) which share the Pacific coast area from the 43° latitude north. The latter with its tree-like habit of growth reminding one of a Mniodendron.

(Group 2. Diplolepideae.)

(Subgroup 2. Diplolepideae Pleurocarpae.)

Family 29. Hypnaceae.

This family is a large one and is variously constituted as to genera depending on the opinions of the different workers. It usually is made to include most of the pleurocarpous mosses with elongated, smooth leaf cells and well developed peristomes.

Dr. A. J. Grout, in his Moss Flora of North America North of Mexico, makes eight subfamilies of the group and points out the fact that characters relied upon in the past as the basis for classification cannot really be relied up in safely because habitat conditions will cause a variation of structures. For instance, xerophytic conditions cause thick leaf cells and the curvature and direction of the capsule are affected by habitats. C. Mueller and Hampe made one genus, Hypnum, which they broke up into sections and subgenera.

The plants are characteristically creeping in habit and have much branched stems which form thick mats. They grow principally on soil and rotten wood, sometimes on stones and tree trunks and few live in water. The creeping nature of the plants is responsible for the generic name, Hypnum, which comes from the Greek word meaning "sleep" . The family is closely related to the Leskeaceae from which it differs principally by having non-papillose leaves.

The deep, moisture-conserving forests at the base of Mount Rainier with the abundance of decaying vegetation, provide an ideal habitat for Hypnaceae. Of the eight subfamilies in North America, representatives of six are found in the park. The distinctions between these subfamilies are shown in the key in the section on Individual Descriptions of Mosses.

Probably the most striking mosses in the park are the large Hylocomieae of which the beautiful Hylocomium splendens and Rhytidiopsis robusta are relatively abundant on rotten wood and on the ground. Some are epiphytes as Rhytidiadelphus loreus which hangs on the dead limbs of trees.

Family 30. Leskeaceae.

This family is divided into three subfamilies, the Anomodonteae, the Leskeae, and the Thuideae, by Dr. Grout in his Moss Flora. The latter subfamily is popularly referred to as the Fern Mosses because of their beautiful fern-like growth habits. Anomodon embraces about 40 species in the forested regions of the northern hemisphere . Forms such as Anomodon minor and A. triste are distributed in eastern Asia and western United States and follow much the same distribution as certain Angiosperms, for example, Hamamelis and Liquidamber.

These mosses are of widely varying habits. They grow commonly on shaded earth, stones and trees, as well as on decayed wood. They are particularly abundant in the whole Puget Sound area where they find favorite growth conditions in the dense forests with an abundance of down timber.

The subfamily Thuideae, or the Fern Mosses, are mosses in which the stems are regularly pinnately branched and ascending in growth habit, thus giving the whole, plant the appearance of a small fern. Host species have paraphyllia and the setae are long and have a tendency to be twisted when dry. The genus Thuidium has a typical hypnaceous peristome.

On Mount Rainier the Thuideae are very abundant in the lower elevations where they are usually found on fallen logs in the dense forests. The Leskeae have a tendency to be in higher elevations and are usually found clinging tightly to the bark of trees or to stones and sometimes on the ground.

Family 31. Hypopterygiaceae.

A small and relatively unimportant family of mosses which has its best development in the southern hemisphere. The plants are slender to robust and are often pinnately branched or dendroid. They grow epiphytically or on rotten tree stumps.

Of this family only one genus and one species has been recorded from North America, namely, Hypopterygium japonicum from off the coast of British Columbia (Queen Charlotte Island). As the specific name indicates, this is a Japanese species which probably owes its spread to the Japan current.

Family 32. Hookeriaceae.

These plants are typically hanging mosses of the tropical regions although Hookeria belongs also to the northern climates, restricted, however, to oceanic regions. Of this genus Hookeria lucens which is is found only along the west coast of our continent, is one of the most beautiful and largest-leaved of all the mosses. Its network of cells is the loosest and softest among the mosses and the leaf cells are so large that they can be seen with a weak magnifier. The capsules are erect or cernuous; the peristome is double and well-developed. So far no members of this family have been collected here by the author.

Family 33. Neckeraceae.

Rather easily recognized mosses found growing usually on rocks and trees. With the exception of Antitrichia curtipendula, these are the only mosses of the northern hemisphere which give us an idea of the appearance of the tropical epiphytes. They hang in long curtains from the trees and rocks. Of the genus Neckera 63% of the species are tropical.

The leaves of this moss group are large and often a shining yellow-green with a striking and easily recognized complanate arrangement on the branches. The branches are irregularly or pinnately branched. The capsules are either immersed or long exserted and the peristome double.

On Mount Rainier the Neckeraceae are particularly abundant in the lower Canadian zone where the temperatures are mild and the moisture ample.

Family 34. Meteoriaceae.

This family is very well named for it is the type form of the hanging mosses which form true associations and formations. The plants are slender to moderately robust with the stems usually regularly pinnate, complanate-foliate or with the leaves equally spreading. Members of the family play no part in building the moss flora of Mount Rainier National Park but are confined to the Gulf region of our country.

Family 35. Pterobryaceae.

Like the above family, this group is tropical or subtropical in habit and distribution, being confined to the Gulf region in our country. Our North American representatives of the family are mostly bright green glossy forms climbing on trees. The secondary stems are spreading and symmetric. Included in this publication merely to complete the discussion.

Family 36. Leucodontaceae.

For the most part the plants of this family are confined to the drier regions of the subtropics. Of the various genera, Leucodon may be designated as boreale. The mosses are generally robust with their stems irregularly branched and not pinnate. The capsule is symmetrical and the peristome usually double. They differ from the Neckeraceae, which mosses they most closely resemble, in their noncomplanate leaves. Only one genus, Pterogonium, has been reported from the west coast.

Family 37. Cryphaecaceae.

A group which shows marked similarity to the Orthotrichaceae and like these messes, they are found growing on trees. The primary stems are creeping while the secondary stems are erect and branched laterally and somewhat pinnately though irregularly.

In the genus Cryphaea the capsules are immersed but in Antitrichia they are exserted. Of the group there are three genera well represented on the Pacific coast, namely, Antitrichia, Alsia, and Dendroalsia. Antitrichia curtipendula var. gigantea is quite abundant on trees between Longmire and the Nisqually entrance.

Family 38. Fabroniaceae.

With the exception of Amblystegiella, these are the smallest and the most delicate of all the pleurocarpous mosses. The plants spread out in thin mats or patches, usually occupying trees. The stems possess no central strand and often produce many erect, simple, or divided branches which are quite julaceous. The large type genus, Fabronia, is distributed over practically the entire warmer region of the earth. The peristome is single, rarely lacking and very hygroscopic.

Family 39. Fontinalaceae, The Water Mosses.

The name of this family originates from the Latin, fontinalis, "belonging to springs and water", and is very descriptive of the habitats of these mosses since all are aquatic. They may be floating forms or usually slender and attached to stones at their bases. Here is a case which is very uncommon among the mosses where the entire family exhibits great uniformity in the growth conditions. The color of the plants varies from green to reddish-brown. The capsule is sessile or sub-sessile and immersed or emergent among a number of closely folded bracts.

In all there are six genera in the family of which three are North American in their range, that is, north of Mexico. These genera are Fontinalis, Dichylema and Brachylema of which only Fontinalis has thus far been found within the park boundaries.

Introduction continued...