Thursday, October 26, 2017

Mosses of Central Florida 35. Pyrrhobryum spiniforme

Pyrrhobryum spiniforme growing in Hawaii.  Photo by Alan

Pyrrhobryum spiniforme (Hedwig) Mitten (Rhizogoniaceae) is a distinctive moss with upright to leaning leafy shoots with narrow, spiny leaves.  The elongate leaves have a strong, conspicuous midrib, and are conspicuously toothed, particularly at the tip and even on the lower side of the midrib.  Leaf cells are roundish, with thick walls

This species occurs mostly at tree bases and on rotting logs. The fresh leafy shoots have a feathery appearance, and the leaves become somewhat twisted or curved when dry. The spore capsules are bent to the side, resembling the heads of birds.  Stalks of the capsules arise from near the bases of the leafy shoots.
The narrow leaf has a strong,
conspicuous midrib, and
prominent teeth along the
A dried specimen of Pyrrhobryum spiniforme,
from Lassiter 643 (USF)

A closer view of the spiny leaf margin and roundish cells of Pyrrhobryum
Pyrrhobryum spiniforme is 
widespread around the world
in the tropics, and in North America is found in Florida and the southern parts of Georgia and the Gulf states to Louisiana. In Florida, we have collections only from Highlands County northward into the panhandle, though it might be expected further south with further exploration.

This species was formerly known as Rhizogonium spiniforme, and often filed under that name.  

Monday, October 23, 2017

Mosses of Central Florida 34. Callicostella pallida

The branching leafy shoots of Callicostella pallida adhere
closely to this piece of decaying wood. Photos from Lassiter 
2028 and 2029 (USF).
Callicostella pallida (Hornschuch) Ångström (Pilotrichaceae) is a small, creeping moss found on tree
bases, exposed roots, rotting logs, limestone, and occasionally on submerged rocks, often in deep shade. The indefinite, branching leafy shoots cling closely to their substrate. The ovate to elliptical leaves are distinctive for their double ribs, which don't reach to the tip.  Leaf cells are roundish to rectangular, with distinctive papillae, at least near the leaf tip. Spore capsules are symmetrical, somewhat swollen but narrowed below the expanded tip, and turned sideways by a bend in the upper stalk.

Callicostella pallida can readily be recognized by the unusual
double ribs.
This species, sometimes filed under the older name, Schizomitrium pallidum, so far is known from Louisiana, Alabama and Florida.  In Florida, it is found from Alachua and Clay Counties southward.

The spore capsules are swollen but constricted below the larger
tip, and bent to the side by a hook near the top of the stalk.
From other members of the family Pilotrichaceae, including Cyclodictyon varians, found in north Florida, with an unverified report from Hillsborough County, Callicostella differs by its more rounded and papillose leaf tip.
The cells at the tip of the leaf are papillose, i.e. contain small, hard,
translucent bumps, seen here as tiny, yellowish bright spots.

Thursday, October 19, 2017

Mosses of Central Florida 33. Rhynchostegium serrulatum

A spreading colony of Rhynchostegium serrulatum.  All
photos by Robert A.Klips, Ohio Moss and Lichen Association.
Rhynchostegium serrulatum (Hedwig) A. Jaeger (Brachytheciaceae) is a spreading, mat-forming
Leaves are notably toothed and the midrib peters out before
the tip. Cells are long and worm-like.
moss found on soil, rotting wood, and tree bases. Leafy stems grow indefinitely with numerous leaves spreading mostly to the two sides of the stem.  Spore capsules arise from along the stems, and are strongly curved.  Leaves are spiny along the margins, particularly toward the tip.  The midrib is relatively weak, generally not reaching the tip.  Leaf cells are elongate and curved, with thick walls, what I often refer to as worm-like.
Spore capsules are strongly arched, with
a swollen tip.

From it's bent spore capsules and spreading leafy stems, this species could be mistaken for the common Isopterygium tenerum. Even the elongate, worm-shaped leaf cells are similar.  But the most obvious difference is the presence of a midrib here, which is lacking in Isopterygium and the greater number of teeth along the leaf margin.  The capsules of Rhynchostegium are also more slender and more bent, almost into a U-shape, but with the tip enlarged and more cone-shaped.  Differences between the Brachystegiaceae and the Hypnaceae, to which Isopterygium belongs, are obscure and technical.

Rhynchostegium serrulatum is found throughout eastern North America, as far west as New Mexico, and north to Ontario and Quebec. In Florida, it appears to be distributed throughout the state.  Gaps in county records are more likely due to lack of collections than absence of the species.

Tuesday, October 17, 2017

Mosses of Central Florida 32. Trematodon longicollis

Trematodon longicollis Michaux (Bruchiaceae) is a fast-growing moss that
colonizes bare soil, forming small clumps.  Stems are short, upright, and bear a few narrow, elongate leaves.  The massive midrib extends to the tip of the leaf.  Leaf cells in the narrow blade on either side of the midrib are irregularly squarish.

Trematodon longicollis appears on bare soil.  This colony appeared in a flower bed that had been turned over just a few weeks earlier.  Note the thick, tapering neck below the more swollen spore chamber.
The most distinctive feature of this moss is the thick, tapering neck below the spore chamber of the capsule.  The neck in this species occupies about 2/3 the length of the capsules, which are curved slightly to the side atop long stalks.
On either side of the massive midrib, one can see the irregular
cells of the blade, that range from squarish to triangular.
Trematodon longicollis occurs in the eastern U.S. as far west as Texas and
Oklahoma, and to Pennsylvania in the north.  In Florida, it has been collected spottily throughout the state.

Friday, October 13, 2017

Mosses of Central Florida 31. Ephemerum crassinervium

The tiny rosettes of Ephemerum crassinervium
appear scattered on a mass of green,
thread like stems (protonemata). Photo by Robert
A. Klips, Ohio Moss and Lichen Association.
Ephemerum crassinervium (Schwaegrichen) Hampe (Ephemeraceae) is a tiny moss that is often overlooked.  As the name implies, it is an ephemeral plant that pops up in disturbed soil along drying shorelines in the dry season, and occasionally on rotting logs.  The plants then disappear again as their habitat is flooded during the rainy season.

The tiny rosettes are only a few mm high, though the spreading leaves may be as much as 2.5 mm long.  Leaves are toothed in the upper 2/3 and papillose (with small, translucent bumps) at the tip.  The midribs are weak, sometimes not evident at the base.  Leaf cells are irregularly long-rectangular and lined up in vertical rows.

The spherical spore capsules are also tiny and
often overlooked. Photo by Robert A Klips,
Ohio Moss and Lichen Association.
The spore capsules, when they appear, are also barely noticeable, as they lack a stalk and remain nestled in the center of the rosette.  The spherical capsules do not open regularly like most other mosses, lacking the typical mouth, teeth, and lids, but eventually rupture irregularly.

Ephemerum crassinervium is found widely in eastern North America, west to Texas and Nebraska, north to Saskatchewan, Ontario and Quebec (but not known in Maine), with some reports from Oregon.  In Florida, it has been sparsely collected from the panhandle to Collier County.

Two additional species have been reported from Florida.  E. cohaerens has been even more sparsely collected throughout north Florida, but not yet in central Floirda.  It differs from E. crassinervium in the smoother cells of the leaf tip, and the leaf cells lined up in diagonal rows.

E. spinulosum has a similar distribution as C. crassinervium, with some in Hillsborough and Manatee counties; cells of the leaf tip are spiny as opposed to smooth or papillose.

Saturday, October 7, 2017

Mosses of Central Florida 30. Atrichum angustatum

For other mosses in this series, see the Table of Contents]

Atrichum angustatum (Bridel) Bruch & Schimper (Polytrichaceae) is a relative of the common Polytrichum commune, but shorter in stature and with distinctly wavy leaves.  The upright stems are 1-2 cm tall, and like other members of the family, have vertical, fin-like sheets of tissue arising from the nidrib. Typically numbering about 10, these lamellae are also wavy.  Polytrichum has up to 20, and these are straight, compact and occupy most of the leaf surface. leaf cells are roundish and bulging to papillose  (with short, hard, translucent bumps).

The upward-facing rosettes of narrow, wavy leaves resemble a tiny bromeliad. The lamellae can be seen along the midrib,  running the length of the leaf. All photos by Robert A. Klips, Ohio Moss and Lichen Association. 
The wavy sheets of tissue, or lamellae, can be seen arising from
the midrib.
Atrichum angustatum occurs throughout eastern North America, as far west as Nebraska and Texas, and as far north as Newfoundland. It can be found typically on exposed soil along roads and trails, as well as on soil exposed by fallen trees. It is uncommon in Florida, with just a few specimens from the northern part of the state down to Manatee County. It has been found in our area on creek banks and Indian mounds.
This reproductive specimen, with its narrowly cylindrical
sporangia, was photographed in Ohio.

This species may be limited in its abundance, in part, because male and female reproductive organs are borne on separate plants, which must occur in close proximity in order to form spores.  Sporangia, when found, are upright and narrowly cylindrical.