Friday, November 17, 2017

Mosses of Central Florida 39. Barbula indica

A dried specimen of Barbula indica,
showing the leaves twisted around the
stems. (from  Merner s.n. 20 Sep 1970,
USF)
Barbula indica (Hooker) Sprengel (Pottiaceae) forms cushions of upright stems as high as 1.2 cm, mostly on limestone rocks. The leaves are narrow-ovate in shape and clearly grooved on the upper surface along the strong midrib, spreading when wet but rolled together and twisted when dry.  Leaf cells are roundish and papillose, with larger clear cells at the base.  Spore capsules are rarely seen in Florida, but when present are upright, more or less symmetrical, and have  long, twisted teeth around the opening.

A piece of limestone with Barbula indica and Hyophiladelphus agraria (with orange capsule stalks near the top) From Newberry s.n. 25 Feb 1971, USF.
This species, usually differentiated as Barbula indica variety indica, is found throughout the world, including much of eastern North America, Alaska and the Canadian Northwest Territories.  In Florida, it has been collected spottily throughout the state.  Another variety,  B. indica var gregaria is found widely in tropical America, but oddly only in Alberta, Canada in North America.

The family Pottiaceae, at least in central Florida, can be recognized by its upright, radially symmetrical shoots, with papillose leaves, and most often occurring on limestone.  Other central Florida genera in the Pottiaceae include Weissia, which has short, rosette-like leafy shoots with narrow, sword-shaped leaves that are strongly inrolled at the edges, and capsule teeth that are short and straight. It is also more likely found on soil.  Hyophiladelphus occurs also on limestone rocks, sometimes mixed with Barbula, and also has long twisted teeth around the opening of the capsule, but has short, rosette-like shoots, and leaves that are only rarely papillose. Tortella  is also similar but the leaves have a very distinctive V-shaped pattern of clear basal cells.

Friday, November 10, 2017

Mosses of Central Florida 38. The genus Neckeropsis

A single leafy shoot of Neckeropsis
disticha
, showing the broad, blunt-tipped
leaves, arranged alternately on the two
sides of the stem. Photo from a rehydrated
herbarium specimen, (Lassiter 892
(USF))
Two species of Neckeropsis (Neckeraceae) occur in Florida: Neckeropsis disticha (Hedwig) Kindberg (Neckeraceae) and Neckeropsis undulata (Hedwig) Reichardt. The two species have a similar growth form, what has been described as "shelf-forming," with flattened, fern-like  leafy shoots that extend horizontally from their attachment to the sides of tree trunks, logs, and sometimes rocks.

The leaves are broad and blunt-tipped, with midribs that don't reach the tip. Leaf cells are roundish near the tip, but more elongate further down. The spore capsules, shaped like champagne glasses, are essentially stalkless, and located along the leafy shoots, nestled within crowns of narrow, bract-like leaves.






The leaves of Neckeropsis undulata are distinctively rippled. Photo by Elizabeth Lavocat Bernard.
The spore capsules of Neckeropsis disticha are scarcely
pushed beyond the leaves by their very short stalks.
Photo by Elizabeth Lavocat Bernard.
Both species of this pantropical genus are found in Florida from Citrus and Semiole Counties southward.  They differ most conspicuously in their leaves.  Those of Neckeropsis undulata are rippled, like crisped ribbons, while those of N. disticha are more or less flat when wet, or slightly wavy when dry.
The spore capsules of Neckeropsis undulata are distinctly
larger than those of N. disticha.  Photo by Elizabeth
Lavocat Bernard.



I am grateful to Elizabeth Lavocat Bernard for permission to use photographs from a blog article on the bryophytes of Guadaloupe on the website MOVECLIM (MOntane VEgetation as listening posts for CLIMate change).

An additional interesting photo displaying the shelf-like growth pattern of this genus can be viewed at:
Neckeropsis undulata by Scott Zona

Wednesday, November 8, 2017

Mosses of Central Florida 37. The genus Thelia

The leafy shoots of Thelia resemble the the scaly shoots of
junipers.  All photos are of T. asprella, and taken by
Robert A. Klips, Ohio Moss and Lichen Association.
The three species of Thelia (Theliaceae) found in Florida have distinctive juniper-like leafy shoots, with short, scale-like leaves that are pressed to the stem even when wet. They include  Thelia asprella (Schimper) Sullivant, T. hirtella  (Hedwig) Sullivant, and T. lescurii Sullivant.  The first two species occur primarily as spreading mats at the bases or trunks of trees, on rotting logs, or soil, but T. lescurii occurs only on soil or thin soil over rocks.
The spore capsules of Thelia are upright, cylindrical and
symmetrical.
The short, stiff leaves typically have only rudimentary, usually forked, midribs at their bases, and the margins are raggedly toothed. Leaf cells are roundish or somewhat elongate, with distinct, columnar papillae. Spore capsules are upright, cylindrical, and symmetrical or slightly curved, atop  stalks that are usually little more than a centimeter high.
The short, broad leaves of Thelia species have ragged edges and elongate papillae.

All three species are found throughout the eastern U.S., including the northern 2/3rds of Florida, though T. lescurii is less common.

Thelia hirtella is distinguished primarily by its simple papillae, as opposed to the branched, compound papillae of the other two species.  In T. lescurii, the leafy shoots are only sparsely branched and tend to be more upright, as opposed to T. asprella, in which the stems spread more horizontally and are densely branched.

The species of Thelia might be confused with Entodon seductrix, which has similar, scale-like leaves, but the leaves of the latter are smooth-margined or with a few small teeth at the tip, and the cells are long, worm-like, and without papillae.

Wednesday, November 1, 2017

Mosses of Central Florida 36. Weissia controversa


A colony of Weissia controversa growing as a low cushion
on landscape fabric around a live oak tree on the campus of
the University of South Florida in Tampa.
Weissia controversa Hedwig (Pottiaceae) is a rosette moss, (i.e. with upright,
short-stemmed shoots, with leaves in a circular arrangement, like a rose), that forms extensive colonies on disturbed soil or sometimes rocks.  The leaves are elongate with a strong midrib that extends beyond the tip in a sharp point.  It is most distinctive in the margins of the leaves that roll tightly inward onto the upper surface (involute). 

The margins of  the long, narrow leaves of
Weissia spp. are distinctively rolled over
the upper surface.
Leaf cells are small, roundish, and papillose (with small, forking bumps), except at the base, where they are larger, rectangular and clear.
Leaf cells are compact, roughly circular, on ether side of the
prominent midrib.

Spore capsules are upright, symmetrical, goblet-shaped, dark brown when mature, and elevated on stalks up to .8 cm in length.
The spore capsules of Weissia controversa are dark brown at maturity, and broadest at the top, like a wine goblet. Most of the capsule here, however, are still topped by their short, beaked lids, or opercula, and some by the outer green sheathes (calyptras).

Weissia controversa is found in nearly every state and province in North America, including Greenland, and in Florida it has been well collected south to Manatee and St. Lucie Counties, but also with reports from Miami-Dade County.

Weissia jamaicensis (Mitten) Grout is a related species, with a more tropical and warm-temperate distribution, found in Florida, Georgia, westward to New Mexico, and north to Missouri, but  not in the Carolinas.  In Florida, it appears to overlap the distribution of W. controversa, but has been much more sparsely collected.  It differs in that the tip of the leaf is usually hood-like, and the base of the leaf flares out into broad shoulders.

Weissia ludoviciana and W. muehlenbergiana  are found throughout eastern N. America and in north Florida.

From other genera in the Pottiaceae, aside from the involute margins, Weissia species differ in their long, narrow leaves. Tortella species are somewhat similar, but not distinctly involute along their margins except sometimes at the tips.  Tortella also differs in the distinct V-shaped region of large, clear cells at the base of the leaf.