Lophocolea appalachiana R. M. Schuster

Distribution

Endemic to southeastern U.S.A. Georgia, Kentucky, North Carolina, South Carolina, Tennessee. Apparently restricted to the Appalachian Plateaus and Blue Ridge physiographic provinces. As recently as 2017 the species was reported to be known from only North Carolina and Tennessee (Stotler and Crandall-Stotler 2017; Schuster 1980).

Habitat

In shaded streams within northern hardwood forests and acidic cove forests usually with Tsuga canadensis and almost always with Rhododendron maximum; moderate elevations (1180 ft – 4000 ft.).

Occurring on wet rock (solid bedrock, wet stones projecting just above water’s surface in quite streamlets, ledges and rocks in the splash zone of waterfalls, sometimes on thin layer of soil over wet rocks) and to a lesser extent on wet woody debris (logs, limbs, and exposed roots at the water’s edge). Often in deep shade. It appears to disperse locally by spores; mats may persist in place for a few years before succession or local perturbations remove them. Though not found in the spray cliffs of the Chattooga Basin (Zartman and Pittillo 1998), Lophocolea appalachiana is a component of spray cliff communities.

Associated bryophytes include: Liverworts: Conocephalum salebrosum, Jubula pennsylvanica, Jungermannia evansii, Pellia appalachiana, Plagiochila porelloides, Riccardia multifida, Scapania undulata; Hornwort: Nothoceros aenigmaticus; and Mosses: Amblystegium tenax, Hookeria acutifolia, Hygohypnum eugyrium, Platylomella lescurii.

The southernmost known occurrence is from Amicalola Mountain in Dawson County, Georgia, occurring with Nothoceros aenigmaticus in a streamlet surrounded by a Kalmia latifolia understory in a mixed hardwood forest.

Brief Description and Tips for Identification

Plants green, forming loose mats. Individual shoots ca. 2 – 2.5 mm wide. Lateral leaves succubously arranged, apex shallowly bilobed to entire. Underleaves bilobed with a deep, U-shaped to V-shaped sinus, each lateral base of the underleaf with or without a lateral tooth; decurrent base of underleaf on one side of the stem often fused with base of a lateral leaf.

Monoicous. Androecia at apices of elongate leafy shoots. Male bracts smaller than lateral vegetative leaves, bract apices rounded, unlobed or rarely a few bracts feebly bilobed. Perianth at apex of short lateral branch or at apex of elongate leafy shoot. Perianths trigonous (with three flat sides), keels of perianth typically winged, the wings often coarsely toothed.

While data on timing of gametangia and spore production is mostly lacking, mature capsules were present in April (Tennessee) and young female shoots (archegoniate) present in July and August (North Carolina, Georgia). Presumably, sporophytes are conceived in mid- to late summer and mature the following spring.

Plants usually possess sexual branches (even if only from past seasons). Androecia offer the one, most reliable character for confident identification. Within the androecium the male bracts are unlobed with rounded apices. The apices of male bracts in the rather similar Lophocolea coadunata (=L. cuspidata) are bilobed. As both species are polymorphous (Schuster 1980), there are few absolute character distinctions between L. appalachiana and L. coadunata (=L. cuspidata). Other than the apices of male bracts, distinctions are subtle. In both species one side of the underleaf base may be connate with base of a lateral leaf; however, this condition is more frequent in L. appalachiana. There is a difference in the degree to which lateral leaf apices are lobed. Those of L. coadunata are usually sharply bilobed, those of L. appalachiana are shallowly bilobed, feebly bilobed with one or two projecting tooth-like lobe apices, or entire.

Androecia also distinguish Lophocolea appalachiana from Chiloscyphus. Regional Chiloscyphus possess lateral leaves whose apices are entire, retuse, or rarely a few leaves are bilobed. Such variation may lead one to consider L. appalachiana for specimens of Chiloscyphus; however, androecial bracts of Chiloscyphus are similar in size to vegetative leaves and perianths are not trigonous and are always born on very short lateral branches.

Salient Features

• Male bracts much smaller that vegetative lateral leaves
• Apices of male bracts entire, rounded
• Lateral leaves shallowly bilobed to entire
• High frequency of underleaf bases connate with base of lateral leaves

References

Schuster, R.M. 1980. The Hepaticae and Anthocerotae of North America East of the Hundredth Meridian. Volume IV. Columbia University Press, New York

Söderström, L., Hagborg, A., von Konrat, M., Bartholomew-Began, S., Bell, D., Briscoe, L., ... & Cooper, E. D. 2016. World checklist of hornworts and liverworts. PhytoKeys, 59(1–2): 1–828.

Stotler, R. E., and Crandall-Stotler, B. 2017. A synopsis of the liverwort flora of North America north of Mexico. Annals of the Missouri Botanical Garden, 102(4), 574-709.

Zartman, C. E., and Pittillo, J. D. 1998. Spray cliff communities of the Chattooga Basin. Castanea, 217-240.

Acknowledgment

Some text and images on this page were originally prepared for the Georgia Department of Natural Resources in 2010, contract number 605-090427 with Paul G. Davison and used here with permission.