BFNA Title: Jamesoniella
Jungermanniaceae - Jamesoniella
XXX. JAMESONIELLA (Spruce) Carrington, London Catalogue of British Mosses, ed. 2, 25. 1881 * [for William Jameson, a Scottish botanist]
Jungermannia subg. Jamesoniella Spruce, Journ. Bot. 14: 202. 1876
Marie L. Hicks
Plants prostrate or forming thick mats or caespitose turfs, green to reddish‑brown or purplish‑black in exposed sites. Stems ascending to erect or prostrate, with few terminal or intercalary branches, either lateral or ventral; sub‑floral innovations common; rhizoids scattered on ventral stem surface, colorless. Leaves alternate, succubous‑oblique, ovate to quadrate‑rotundate, entire, rarely with retuse apices; leaf cell walls moderately thickened; trigones present; oil bodies finely granular, more than 5 per cell. Underleaves absent, or vestigial, occasional and very small, hidden among rhizoids. Specialized asexual reproduction absent. Sexual condition dioicous. Androecia terminal, becoming intercalary; bracts saccate at base with an infolded dorsal tooth; antheridia 1‑‑2 per bract, stalk 2 or 4‑seriate. Gynoecia terminal on main shoot; bracts entire to dentate, laciniate or ciliate on lateral margins; bracteole present, dentate to laciniate‑ciliate; perianth exerted 1/2 or more above bracts, inflated, oblong to fusiform, smooth cylindrical below, 4‑‑5 plicate distally, narrowed to a ciliate or dentate‑crenulate mouth; perigynium absent. Sporophyte seta massive, of numerous cell rows; capsule ovoid, 4‑valved, walls 4‑‑5-stratose; epidermal cells with nodular thickenings, inner cells with semi‑annular bands; elaters 150‑‑200 × 8 µm, 2‑spiral; spores 10‑‑15 µm, finely granular‑papillose.
Species 14 (2 in the flora): tropical and temperate areas of North America, Mexico, Central America, South America, Europe, Asia; s Africa, Australia, Pacific Islands (New Zealand).
Jamesoniella is easily recognized when fruiting by the dentate to laciniate bracts and bracteole, not found in other entire‑leaved genera in the flora. Sterile material may be separated from Odontoschisma by the larger number of smaller oil bodies in leaf cells of Jamesoniella.
SELECTED REFERENCES Schuster, R.M., 1983, New Manual of Bryology 1: 605. Nichinan.
1. Perianth mouth ciliate; female bracts laciniate‑ciliate; leaves not undulate ..........1. Jamesoniella autumnalis
1. Perianth mouth dentate‑crenulate; female bracts with vestigial cilia; leaves commonly undulate . . . . 2. Jamesoniella undulifolia
1. Jamesoniella autumnalis (De Candolle) Stephani, Spec. Hep. 2: 92.1901
Jungermannia autumnalis De Candolle, Fl. Francaise 6: 202. 1815
Plants with shoots 10‑‑30 × 1.5‑‑2.5 mm, prostrate, forming patches or thick mats, green to reddish brown; branches few. Stems stout, ca. 250‑‑300 µm; branching terminal type (base of branch with a lanceolate half‑leaf) or occasionally lateral intercalary; cortical cells thin‑walled, 25‑‑30 µm, medullary cells similar with slightly thicker walls. Leaves imbricate, widely spreading, ovate to rounded‑quadrate, 950‑‑1100 × 950‑‑1150 µm, the apex rounded to slightly retuse; leaf cell lumen rounded, sub‑quadrate to hexagonal, median cells 25‑‑35 × 28‑‑40 µm; marginal cells slightly smaller, ca. 22‑-25 µm; cuticle slightly verruculose‑striolate near leaf base; cell walls thin, trigones with concave sides, not bulging; oil bodies 7‑‑15 per cell, ovoid to ellipsoidal, 3‑‑5 × 5‑‑9 mu, finely granular. Underleaves absent or occasional and subulate near stem apex. Androecia terminal, spicate, eventually becoming intercalary; bracts in 4‑‑6 pairs, imbricate, slightly smaller than leaves, the dorsal base ampliate with 1‑‑2 inrolled teeth; antheridium one per bract; stalk 2‑seriate. Gynoecia terminal on main shoot with 1‑‑2 subfloral innovations; bracts larger than leaves, 1‑‑1.2 × 0.9‑‑1.2 mm, sheathing at base, spreading distally, rounded to retuse with 1‑‑2 laciniate teeth or cilia on lateral margins, the base narrowly connate with bracteole; bracteole large, 0.3‑‑0.4 mm with several laciniate‑ciliate lobes; perianth cylindrical to fusiform, 3‑‑3.5 mm, distall portion 4‑‑5 plicate, narrowed to laciniate‑ciliate mouth, cilia 5‑‑10 cells long.
Humus‑rich soil, rock, logs or tree bases in moist temperate deciduous or Spruce‑fir forests; Alta; B.C. N.B., Nfld., N.S., Ont. Que.; Alaska, Conn, Fla., Idaho, Ill., Ind., Iowa., Kans., Ky., Maine, Md., Mass., Mich., Minn., Miss., Mo., N.H., N.J., N.Y., N.C., Ohio, Ore., Pa., R.I., S.C., Tenn., Vt., Va., Wash., W.Va., Wis., Wyo.; Mexico; Europe; Asia.
Minor varieties have been reported from single sites in the flora area. Jamesoniella autumnalis var. myriocarpa (Brinkman) Frye and L. Clark is an inadequately described plant from a site in Nova Scotia; the Japanese J. autumnalis var. nipponica (S. Hattori) S. Hattori was reported from a site in Virginia, and the more robust J. autumnalis var. heterostipa (A. Evans) Frye & L. Clark from Quebec. Jamesoniella autumnalis is subject to environmental variation and the differences on which these varieties are based are poorly understood. These plants are most likely environmental variants.
2. Jamesoniella undulifolia (Nees) K. Müller, Rabenhorst Krypt.‑Fl. 6(2): 758. 1916
Jamesoniella schraderi var. undulifolia Nees, Naturg. Eur. Leberm. 1: 306. 1833
Plants with shoots 10‑‑30 cm × 1‑‑1.5 mm, prostrate to erect‑caespitose when crowded, slightly laterally compressed, simple or with few branches, green to reddish‑brown. Stems firm, 225‑‑275 µm; branches terminal, long; cortical cells 14‑‑20 µm with thin walls, medullary cells slightly larger. Leaves imbricate, orbicular, wider than long, 0.8‑‑0.85 × 0.95‑‑1.1 mm, slightly concave, the larger leaves tending to be undulate; margins broadly rounded, entire, emarginate leaves occasional; median leaf cells 22‑‑26 × 25‑‑34 µm; marginal cells 20‑‑25 µm; cuticle faintly verruculose; cell walls slightly thickened; trigones present, occasionally slightly bulging; oil bodies 6‑‑12 per cell, spherical to ellipsoid, 4‑‑5 × 6‑‑8 µm, granular. Underleaves absent or sporadically present on sterile shoots, very small, lanceolate or of slime papillae. Androecia terminal becoming intercalary; bracts in 4‑‑6 pairs, imbricate, concave with an incurved tooth at dorsal base; antheridia two per bract, stalk 4‑seriate. Gynoecia (frequently fertile) terminal on main shoot with large somewhat undulate subtending leaves; bracts large, up to 800 × 1200 µm, undulate, similar to distal leaves with small, obscure teeth on margins; bracteole free, large (to 650 µm), lanceolate with 1‑‑2 teeth at base; perianth ovoid‑oblong, inflated, contracted to plicate mouth with small 1‑‑2 celled teeth or crenulate margin formed by elongate fingerlike cells.
Peaty soil in bogs or among mosses on tundra; w and nw Greenland; n Europe.
Jamesoniella undulifolia has been treated recently (Konstantinova and Vilnet 2009) as Biantheridion undulifolium (Nees) Konstat. & Vilnet.
SELECTED REFERENCE Konstantinova, N. A. and A. A. Vilnet. 2009 (2010). New taxa and new combinations in Jungermanniales (Hepaticae). Arctoa 18: 67--67.