Amblystegiaceae |
Pseudocampylium |
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Habit | Plants small to large, green, yellowish, or brownish. | Plants small, light green to yellowish. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stem(s) | leaves straight, falcate, or squarrose, plicate or not; costa single, usually long, or double and usually short; alar cells differentiated or not, sometimes inflated; medial laminal cells linear or short-linear, rarely rectangular or hexagonal, 1-stratose or sometimes partially 2- or multistratose, smooth or rarely prorate or papillose. |
leaves wide-spreading to squarrose, cordate-ovate, not plicate, 0.5–0.7 mm; base narrowed, decurrent, concave at basal angles; margins plane or slightly recurved in alar region, entire or nearly so, limbidia absent; apex long-acuminate, acumen furrowed; costa single, to 1/2–3/4 leaf length, terminal abaxial spine absent; alar cells differentiated, somewhat inflated, hyaline, widest cells 14–25 µm wide; distal laminal cells smooth. |
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Seta | long or rarely short, smooth. |
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Sexual condition | autoicous. |
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Capsule | horizontal to erect, cylindric or short-cylindric, curved to straight; stomata with long pores; annulus separating or not; operculum conic, rarely rostrate or short-rostrate; peristome perfect or specialized; perfect exostomes yellow-brown or brownish, external surface cross striolate or sometimes reticulate proximally, papillose distally, margins dentate or slightly dentate, border ± widened at transitional zone in outer peristomial layer pattern; specialized exostome teeth variously narrow or short, external surface sometimes papillose basally; perfect endostome basal membrane high, segments long, not or narrowly perforate, cilia nodose or sometimes appendiculate; specialized endostome basal membrane ± reduced or sometimes absent, segments narrower, sometimes shorter than in perfect endostomes, cilia short to absent. |
horizontal, subcylindric, curved; peristome perfect; exostome margins dentate distally; endostome cilia nodose. |
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Calyptra | cucullate, smooth. |
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Spores | 9–18 µm. |
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Perichaetia | with inner leaves erect, straight, lanceolate, ovate, oblong, or slightly obovate, plicate or rarely not, margins entire or partly denticulate, apex usually acuminate, costa single or double, usually well developed, laminal cells usually smooth; paraphyses present. |
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Amblystegiaceae |
Pseudocampylium |
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Distribution | Nearly worldwide; temperate to subpolar regions; tropical mountains |
North America; Mexico; Central America; Europe |
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Discussion | Genera 20–30, species 100–150 (20 genera, 57 species in the flora). Amblystegiaceae as here circumscribed include several genera or species groups that may not or are even unlikely to belong to this family in a strict sense. These include Calliergonella, Campylophyllum, Conardia, most of Hygrohypnum, Limbella, Platydictya jungermannioides, Platylomella, Sanionia, and Tomentypnum. The genus Amblystegium is here understood in a broad sense, including Hygroamblystegium but excluding Serpoleskea (here treated in Platydictya). Amblystegiaceae is sometimes confused with other pleurocarpous families, such as Brachytheciaceae and Plagiotheciaceae. Most Brachytheciaceae and Plagiotheciaceae differ from Amblystegiaceae in their non-plicate and often recurved, rather than plicate and erect, inner perichaetial leaves (in species with horizontal capsules). In Brachytheciaceae, horizontal capsules are swollen rather than cylindric, the stomata round-pored rather than long-pored, and the exostome base is mostly red or brown-red rather than yellow-brown. The exostome teeth borders are gradually narrowed upwards rather than suddenly widened where the exterior pattern of the teeth changes from cross striolate to papillose, the endostome segments are widely rather than narrowly perforate, and the spores mature in winter rather than summer in temperate areas. Plagiotheciaceae members have pale whitish yellow exostomes and differ from Amblystegiaceae in several diagnostic gametophyte features, including rhizoid position and ornamentation, and branching mode (see 4. Platydictya treatment). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species 1. Pseudocampylium radicale, the only species in the genus, has been placed among Campylium, Leptodictyum, and most recently, Amblystegium. Its slender habit is reminiscent of Amblystegium serpens, while its wide-spreading to squarrose leaves recall Campylium, and its fairly long laminal cells are somewhat similar to those of Leptodictyum. Molecular evidence shows that P. radicale is unrelated to these genera and is nested within a clade including similarly slender species with a weak or even absent costa, including Pseudoamblystegium subtile and Serpoleskea confervoides, but also a morphologically heterogeneous assemblage of genera including Anacamptodon and Hygrohypnum. All these taxa have fairly narrow ecological ranges, and it seems that habitat specialization has triggered an array of contrasting morphologies among taxa that share a common ancestor. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Source | FNA vol. 28, p. 263. | FNA vol. 28, p. 305. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Name authority | G. Roth | Vanderpoorten & Hedenas: J. Bryol. 31: 131. (2009) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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