Sematophyllum

Mitten

J. Linn. Soc., Bot. 8: 5. 1864

Etymology: Greek sematos, mark, and phyllon, leaf, alluding to inflated row of alar cells
Treatment appears in FNA Volume 28. Treatment on page 573. Mentioned on page 535, 572, 574, 575, 644, 646.
Plants small to large, green, yellow-green, golden yellow, or golden brown, glossy or dull. Stems 0.3–5 cm, not complanate-foliate, irregularly branched. Leaves erect-spreading to falcate-secund, often homomallous, oblong-lanceolate, oblong-ovate, or ovate; margins entire; apex acute to acuminate; ecostate or costa double; alar cells elongate, somewhat to strongly enlarged and inflated, pigmented or rarely unpigmented, walls thin, region in 1–several rows, middle lamella not apparent, supra-alar cells differentiated; laminal cells rhomboidal, elliptic, or flexuose, smooth. Sexual condition autoicous [dioicous]. Seta 0.4–2 cm. Capsule inclined to horizontal or rarely erect, short-cylindric; exothecial cell walls collenchymatous; operculum rostrate.

Distribution

Nearly worldwide, temperate to pantropical regions.

Discussion

Species ca. 50 (4 in the flora).

As W. R. Buck (1998b) has noted, Sematophyllum is a catch-all genus in need of a world monograph; however, the four North American species are reasonably treated in Sematophyllum. The genus is confined to eastern forests in the flora area, and introduced to California, where it is rare. The plants have red-brown stems with foliose pseudoparaphyllia; the medial laminal cells are rhomboidal to flexuose.

Selected References

None.

Key

1 Leaves tapering abruptly to apex; plants dull. Sematophyllum subpinnatum
1 Leaves tapering gradually to apex; plants glossy > 2
2 Plants medium-sized to large; leaves 1.5-2 mm; alar cells in several rows; usually on rock. Sematophyllum marylandicum
2 Plants small to medium-sized; leaves usually less than 1.4 mm; alar cells in 1 row; epiphytic or occasionally on rock > 3
3 Capsules erect; growing on wood, logs, tree bases, occasionally rock. Sematophyllum adnatum
3 Capsules inclined to horizontal; commonly growing on rock near streams. Sematophyllum demissum