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fissidens moss, yew-leaf pocket moss

Appalachian fissidens moss

Habit Plants to 11 × 3.5 mm. Plants to 13 × 2–4 mm.
Stem

mostly branched;

axillary hyaline nodules absent;

central strand present.

unbranched and branched;

axillary hyaline nodules weak or absent;

central strand weak.

Leaves

as many as 15 pairs, often undulate, oblong to lanceolate, obtuse to broadly acute, cuspidate, to 2.7 mm × 0.6 mm;

dorsal lamina truncate-rounded proximally, ending at insertion, not decurrent;

vaginant laminae 2/3 the leaf length, ± equal, minor lamina ending on or near margin;

margin evenly serrulate, often crenulate-serrulate on dorsal and ventral laminae, elimbate;

costa ending in cuspidate apex, taxifolius-type;

laminal cells 1-stratose, distinct, smooth, bulging, firm-walled, irregularly hexagonal, 8–11 µm frequently paler at margin, conspicuously mammillose in vaginant laminae, larger and clearer juxtacostally.

as many as 22 pairs, ligulate to oblong-lanceolate, obtuse-mucronate to acute, to 4 × 0.3–0.5 mm;

dorsal lamina narrowed proximally, ending at insertion or slightly before;

vaginant laminae 1/2–2/3 leaf length, equal in proximal leaves, unequal in distal leaves, minor lamina ending between margin and costa or rounded and ending on or near costa;

margin entire but sometimes serrulate distally, limbate on all laminae, limbidium confluent at apex or ending a few cells before, limbidial cells 2- to 5-stratose;

costa percurrent or ending in mucro, bryoides-type;

laminal cells 1- to irregularly 2-stratose, smooth, slightly bulging, firm-walled, irregularly hexagonal, many somewhat elongate, 10–16 µm, juxtacostal and basal cells of vaginant laminae somewhat larger, quadrate to oblong.

Seta

to 17 mm.

4–4.5 mm.

Sexual condition

rhizautoicous;

perigonia on short branches proximal to elongate stems;

perichaetia on short, proximal, axillary branches.

rhizautoicous or synoicous;

perigonia and perichaetia on elongate stems.

Capsule

theca slightly inclined, slightly arcuate, bilaterally symmetric, to 1.5 mm;

peristome taxifolius-type;

operculum to 1 mm.

theca exserted, erect, radially symmetric to slightly inclined, bilaterally symmetric, 0.6–0.85 mm;

peristome bryoides-type;

operculum 0.4 mm.

Calyptra

cucullate, smooth, to 2 mm.

not seen.

Spores

13–18 µm.

14–25 µm.

Sporophytes

1 per perichaetium.

1–2 per perichaetium.

Fissidens taxifolius

Fissidens appalachensis

Habitat Damp, shaded soil, humus, and rocks Crevices and surfaces of rocks submerged in swiftly flowing but usually shallow water, sometimes partially emergent
Distribution
from FNA
AL; AR; AZ; CA; DC; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; ME; MI; MO; MS; NC; NE; NH; NJ; NY; OH; OK; OR; PA; SC; TN; TX; VA; VT; WA; WI; WV; NS; NT; ON; PE; QC; Mexico; Central America; West Indies; South America (Brazil and Chile); Europe; Asia (China, Japan); Pacific Islands (New Zealand)
[WildflowerSearch map]
from FNA
NC; PA; SC; TN
Discussion

Fissidens taxifolius is distinguished by evenly serrulate or crenulate-serrulate leaf margin, stout costa ending in leaf cusp, conspicuous mammillose cells in the vaginant laminae, and sporophytes on short branches in the axils of proximal leaves. It can be confused with F. bushii, but that species is smaller, has costa shorter, and cells in the vaginant laminae have small, more or less inconspicuous papillae in the corners of the walls. Fissidens taxifolius usually occurs on shaded, damp soil or humus, whereas F. bushii is usually found on disturbed soil in woods, along paths, and in road cuts. Fissidens clebschii is considered to be a freakish expression of F. taxifolius (R. A. Pursell 2003).

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Fissidens appalachensis, restricted to rapidly moving water, is distinguished by its habitat and strong limbidium. It is most likely to be confused with an expression of F. bryoides that is usually found on wet rocks and stones along the edges of streams, but which differs in its smaller size and weaker limbidium that at times can be partially or completely absent. Laminal cells in size and shape, vaginant laminae, sexuality, thecae, and peristomes in both taxa are similar.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source FNA vol. 27, p. 341. FNA vol. 27, p. 344.
Parent taxa Fissidentaceae > Fissidens Fissidentaceae > Fissidens
Sibling taxa
F. adianthoides, F. amoenus, F. aphelotaxifolius, F. appalachensis, F. arcticus, F. asplenioides, F. bryoides, F. bushii, F. closteri, F. crispus, F. curvatus, F. dubius, F. elegans, F. exilis, F. fontanus, F. grandifrons, F. hallianus, F. hyalinus, F. leptophyllus, F. littlei, F. minutulus, F. obtusifolius, F. osmundioides, F. pallidinervis, F. pauperculus, F. pellucidus, F. polypodioides, F. santa-clarensis, F. scalaris, F. serratus, F. subbasilaris, F. sublimbatus, F. submarginatus, F. taylorii, F. ventricosus, F. zollingeri
F. adianthoides, F. amoenus, F. aphelotaxifolius, F. arcticus, F. asplenioides, F. bryoides, F. bushii, F. closteri, F. crispus, F. curvatus, F. dubius, F. elegans, F. exilis, F. fontanus, F. grandifrons, F. hallianus, F. hyalinus, F. leptophyllus, F. littlei, F. minutulus, F. obtusifolius, F. osmundioides, F. pallidinervis, F. pauperculus, F. pellucidus, F. polypodioides, F. santa-clarensis, F. scalaris, F. serratus, F. subbasilaris, F. sublimbatus, F. submarginatus, F. taxifolius, F. taylorii, F. ventricosus, F. zollingeri
Synonyms F. clebschii
Name authority Hedwig: Sp. Musc. Frond., 155, plate 39, figs. 1–5. (1801) R. H. Zander: Bryologist 72: 406, figs. 1–8. (1969)
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