Coniferous Forest Bryophytes

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Descriptions are based on Crum and Anderson (1981) and Crum (1983).

Mosses

Leucobryum glaucum (Hedw.) Ångstr. in Fries

The most distinguishing characteristic of this species is its color. It has been described as whitish, grayish, or a bluish-green. It is variable in size, with individual shoots 2-9 cm tall. It is an acrocap which most often forms densely packed hemispherical cushions, but can sometimes be found forming more continuous hummocks. The density of the shoots and other morphological features contribute to this species high water holding capacity, often soaking the unsuspecting hiker as they sit on a nice soft patch of this moss.

The leaves of this species are relatively large, 3-8 mm in length. They are often erect spreading in orientation, though sometimes somewhat turned to one-side, ie. subsecund. The leaves of this species appears thick due to a very broad costa. Though not readily discernible in the field the costa in cross-section near the base of the leaf has a layer of smaller green cells (chlorocysts) surrounded by 2-3 layers above and 3-4 layers below of large hyaline cells known as leucocysts. It is these leucocysts that contribute to this plants water holding ability. Though rare in this species the sporophytes are made up of a 9-17mm long setae, which when mature is red-brown and a strongly inclined and curved capsule, which can be 1.5-2 mm in length.

Leaf cross-section showing the thick costa with several layers of leucocysts and the arrow indicating the single central layer of chlorocysts (Left) and a section through a shoot showing the arrangement of the leaves (Right).

This species can be found growing on humus or humic soils in moist forests, often associated with the remains of highly decayed logs and stumps. It has widespread distribution in the Eastern North America, throughout Europe, and into Asia.

A related species is:

Leucobryum albidum (Brid. ex P.-Beauv.) Lindb.

L. albidum can be mistaken for this L. glaucum due to their similarity in habit and coloration. It forms gray-green cushions that are only 6-9 mm tall, though sometimes up to 4.5 cm deep. It is generally smaller with leaves of 2-4 mm in length and in cross-section the costa has fewer leucocysts (only 2 to sometimes 3) above and below the chlorophyllose cells. This species is also more commonly found with sporophytes. The setae of which are brown or orange-red and only 8-12 mm long. The capsules strongly inclined and curved, but are shorter than those of L. glaucum, only 1-1.5 mm long.

A large cushion of Leucobryum albidum with its prominent sporophytes making it easy to understand how it received its common name, “The Pin Cushion Moss”.

This species can be found growing on moist rotten logs and stumps, and is one of the few species of moss that grows on the bark of pines. This species is also widely distributed in Eastern North America, but it is considered to be more common southward ranging into Mexico and Central America.

Brotherella recurvans (Mx.) Fl.

This species forms smooth shiny green, yellow, or golden mats. The shoots are sub-pinnately branched with crowded leaves and complanate giving the branches an overall flattened appearance. The leaves also have secund or downward curving tips giving this moss an appearance similar to Hypnum. The leaves are only 1-1.4 mm in length. Another distinguishing feature of this species is the inflated alar cells, which are only observable under a microscope. The sporophyte has an orange-brown setae that is between 7-17 mm tall and is topped by a smooth, brown capsule 1-1.5 mm in length. The capsule is asymmetric, oblong-cylindric and is variably oriented from sub-erect to strongly inclined.

Notice the shiny, flattened shoots of this smooth mat of B. recurvans with sporophytes (Left) and the large, bubbly alar cells which are so distinctive (Right).

It is found growing on rotten logs, soil, humus and tree bases in moist woods.

The species is common and widespread in eastern North America, especially in the north or montane regions.

Pleurozium schreberi (Brid.) Mitt.

The shoots of this species are suberect and stand 7-16 cm high and irregularly pinnately branched. The stems are red and distinctly visible through the shiny yellow leaves. The stem leaves are 1.8-2.4 mm long. Though commonly produced by this species, the sporophytes are often not readily observable because they rarely extend beyond the surface of the tufts. The sporophytes have setae that are 20-43 mm long topped by a capsule 2-2.5 mm in length.

Shoots of P. schreberi showing the pinnately branching and distinct orange-red stems (Left), an individual leaf showing the overall shape and particularly the distinctive tip with the inrolled margins (Middle), and a shoot tip which shows how those leaf tips are recurved, a very distinctive field character (Right).

It is commonly found growing on humus, soil and logs in dry, open woodlands or in bogs and wet conifer forests.

This species is very common in north-eastern North America, and it extends southward and can be found generally at higher elevations. It can also be found in western North America and south in to Central and South America. It is also found in Europe and Asia.

Rhytidiadelphus triquetrus (Hedw.) Warnst.

This is a very robust moss which grows in loose yellow-green, dark-green, or bright-green wefts with individual shoots up to 20 cm tall. It can be irregularly and unequally branched or sometimes closely and equally branched with branches arising horizontally and tapering to their tips in various directions around the stem. The stems and branches are orange-red with erect to erect-spreading leaves. The large (3.5-5 mm long) stem leaves are ovate-cordate and broadly acuminate in shape. They are noticeable plicate with plane margins that are serrate in the upper half. The branch leaves are similar though smaller (1.5-3 mm long). The sporophyte has a 15-45 mm long setae and a red-brown capsule that is 2-3 mm long.

A shoot of R. triquetrus (Left), the leaf base of R. triquetrus showing the long double costa and placations (Middle) and the apiculate leaf tip (Right).

It grows on humus, soil or sometimes on logs and stumps in dry or moist conifer forests.

It is found in north of North American, but has a distribution that extends south in montane regions. It is widespread in Europe and found in Asia.

Tetraphis pellucida Hedw.

This acrocarpous species is small, growing to only 8-15 mm tall. It generally forms fairly dense turfs of shoots that are dull green or red-brown above and rusty-brown below. The leaves are erect spreading and plane with entire margins with a distinct costa (midrib). The leaves along the stem vary in appearance and arrangement. The lower leaves are small and distant ovate- acute and somewhat smaller, only 1-2 mm long while the leaves become longer, narrower, and more crowded toward the shoot tips with the uppermost leaves lanceolate and long acuminate up to 3 mm long. Vegetative shoots often have gemmae cups at the very tip, which are formed from separate bracts and contain many green egg shaped gemmae. The sporophytes have setae 6-14 mm long and are twisted when dry. The 2-3 mm long capsules stand erect are symmetric and narrowly cylindric, red or brown near the mouth and possess 4 large peristome teeth which can be observed with a magnifying lens in the field. Often colonies will contain both the gemmae cups and sporophytes.

T. pellucida growing on a rotting stump (Left), a close-up showing the characteristic gemmae cups in the foreground and the sporophytes in the background (Middle), and several vegetative and reproductive shoots of T. pellucida growing amongst Leucobryum sp. notice the rusty colored shoots in the lower right and the gemmae cups on the shoots in the upper left (Right).

The habitat is as important in identifying this species as the morphology. It is most often found growing on stumps and logs in a high degree of decay (soft), or on peaty soils, and it can sometimes be found on moist sandstone associated with streams.

This species can be found across North America, and also in Europe and Asia.

Hypnum imponens Hedw.

This pleurocarpous species is fairly large with regularly pinnate branching which gives the shoots a triangular frond-like appearance. The creeping stems form often extensive layered mats. The color is variable ranging from yellow-brown to green. The leaves are falcate-secund. When examined under the microscope it is possible to observe numerous, variably shaped pseudoparaphyllia (look for these along the stem when leaves have been stripped). The leaf margins can be slightly toothed in the upper half. The cells along the bottom of the leaf often have colored (orange) cell walls. The alar cells are quadrate (squarish) and form conspicuous groups, above a layer of inflated cells. The sporophytes when present can stand 1 to 3.5 cm tall with a red setae and sub-erect red-brown capsules (2.5-3mm long).

A mat of Hypnum imponens showing the distinctive triangular shoots and arrangement of the leaves (Left) and a patch of H. imponens growing with Dicranum scoparium (Right).

A close-up of a shoot tip showing the falcate-secund leaves and their arrangement on the stem giving it a braided appearance (Left), an individual leaf (Middle Left), the alar region (Middle), the foliose paraphyllia which are indicative of this species of Hypnum (Middle Right), and another paraphyllia showing the variability within the species (Right).

The habitat is as important in identifying this species as the morphology. It is most often found growing on stumps and logs in a high degree of decay (soft), or on peaty soils, and it can sometimes be found on moist sandstone associated with streams.

This species can be found across North America, and also in Europe and Asia.

Hylocomium splendens (Hedw.) Schimp. in B.S.G.

This species forms dull, green, yellowish, or brownish wefts often quite tall. It has a very open and airy architecture supported by the reddish stiff and wiry stems with regularly 2-3 pinnate horizontal fronds, which are arranged in steps. The steps arise from the center of the previous step and each represents a year’s growth. The loosely erect stem leaves are 2-3 mm long and lightly plicate. The branch leaves are much smaller and difficult to distinguish in the field. The sporophyte has an orange-brown or reddish setae that is 12-30 mm long topped by a brown capsule 1.5-2.7 mm long.

A weft of H. splendens (Left) and an individual shoot showing the step-like structure formed by the yearly innovations (Right).

A close-up of a shoot showing the paraphllia, which is quite abundant along the stems (Left), a single leaf showing the roughened nature (Middle), and a close-up of the leaf showing that the upturned ends of the cells are the reason for the rough leaves (Right).

A very common species in northern and montane habitats such as moist coniferous forests. It often grows on soil, humus and as a component species on moist moss covered logs.

This species can be found across northern North America and south in the East in higher elevations. It is also widespread in Europe and Asia with reports from specific regions in the southern hemisphere.

Ptilium crista-castrensis (Hedw.) De Not.

The plants form shiny green to golden colored wefts 3.5-11 cm high. The individual shoots are erect-ascending and pinnately branched forming feathery fronds, which give rise to the common name the “Knight’s Plume Moss”. Both stem and branch leaves are long acuminate and plicate. The stem leaves are larger, 2-3 mm long, and loosely falcate-secund while the branch leaves are only 1.2-2 mm and distinctly secund. The sporophytes have red setae 24-45 mm and nearly horizontal chestnut-brown capsules that are 2-3 mm long.

Very distinctive shoots of P. crista-castrensis it is not difficult to see how they get the name “Knight’s Plume” moss (Left) and another wonderful picture of this beautiful moss (Right).

It is found on humus and mixed in with a variety of species on old, moss-covered logs in dry to swampy conifer forests. It is often associated with species of Hylocomium, Rhytidiadelphus, and Pleurozium schreberi.

It is distributed across northern North America and south to upland areas in the East. This species can also be found in Europe and Asia.

Dicranum scoparium Hedw.

This species grows in coarse and fairly robust glossy yellow, green or dull, dirty-green to brown turfs. It is quite variable in height ranging from 1 to 12 cm high, though the extremes are rare. The leaf arrangement can be erect-spreading or appressed, but they are most often falcate-secund, this leads to a general appearance of all the leaves swept in the same direction giving rise to its common name “The Broom Moss”. Drying of the plants causes little change in the arrangement of the leaves. The stems are covered by a dense rhizoid tomentum. The leaves are also variable in several aspects. The leaves can be 3.5-12 mm in length. In shape they can be narrowly or broadly lanceolate, gradually narrowing toward the tip which can be keeled or rarely subtubulose. Though sometimes slightly undulate, the leaves are generally strongly serrate in the upper 1/3 with a strong costa extending into the leaf tip and sometimes beyond. The sporophyte has a yellow setae that becomes red with age that grows to 18-35 mm in length. The suberect to horizontal capsule is curved and 2-3.5 mm long. The capsule can be smooth or as it ages it may become furrowed.

Here is a turf of D. scoparium growing on a rock. Notice the swept appearance of the leaves which give this moss its common names “The Broom Moss” or “The Wind Swept Moss”.

This species commonly grows on soil or humus, but it can also be found growing on rock, at the base of trees and on rotten wood. It can be found in dry and open woodlands and also in dense moist forests.

It found throughout eastern North America and in the West in the mountains. It also has a wide distribution in Europe, Asia, and Australia.

Plagiothecium laetum Schimp. in B.S.G.

This is a relatively small species that forms very shiny bright-green to yellow-green or sometimes golden mats. It is often found growing steep, near vertical banks and is recognized by its very flattened habit. The leaves are complanate, overlapping, and 1.2-1.5 mm long. Under a microscope the leaves are noticeably asymmetric. Also apparent under magnification are the distinct decurrencies at the base of the leaves. The sporophyte has a setae that is from 8 to 20 mm in length with a pale, yellow-brown, symmetric, sub-erect capsule that is 1.5 to 2 mm long.

A mat of P. laetum showing the characteristic habit growing on a near vertical surface with its “Wet Cat” appearance.

It can be found on soil, rotten wood, and soil and humus overlying rock.

This species is common across the northern portions of North America, stretching southward, especially in the mountains. It is also known from Europe and Asia.

Liverworts

Bazzania trilobata (L.) S. Gray

Generally an easily recognizable liverwort species as it often grows in extensive pure green to olive-green mats, though sometimes it can form deep tufts. The individual stems are often forked with flagilliform branches growing downward from the underside of the shoot. The leaves overlap with the leading edge above the trailing edge of the leaf just above it on the stem (when viewed from the upper surface of the shoot). The leaves rectangular-ovate in shape with three large triangular teeth across the broad tip, which is distinguishable in the field. Very rarely will this species be observed with a sporophyte.

The shoots of B. trilobata showing the forked branching and the characteristic shape of the shoots sometimes described as millipede-like (Left), B. trilobata growing with Leucobryum glaucum (Middle), and an individual shoot with filliform branches indicated by the arrow (Right).

The underside of a shoot showing the attachment of the filliform branches and the underleaves which are attached along the stem, a characteristic feature of many leafy liverworts (Left), a leaf tip showing the three triangular teeth (Middle), and the leaf cells showing the thickened corners and the shape and number of oil bodies, the shiny structures within the cells (Right).

It is commonly found in moist forests growing on humus, but can also be observed on rocks, soil, logs, and tree bases. It ranges through much of Eastern North America and into the west, but in its southern range it is more common in the mountains.

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All photos were taken by Keith C. Bowman

Last Updated February 22, 2007.