BFNA Title: Takakiaceae
Author: J. R. Spence & W. B. Schofield
Date: February 22, 2005
Edit Level: 1 Brum+
Version: 1

Bryophyte Flora of North America, Provisional Publication
Missouri Botanical Garden
BFNA Web site: http://www.mobot.org/plantscience/BFNA/bfnamenu.htm

XX. TAKAKIACEAE

J. R. Spence

W. B. Schofield

Stems erect, arising sympodially from creeping pale or white stolons bearing clusters of beaked slime cells, rhizoids lacking, stem in cross-section differentiated into an outer layer of smaller, thick-walled cells and a cortex of larger thin-walled cells, sometimes with small central cells, these often with trigones, outer cells with simple oil droplets. Leaves typically 3-ranked, terete, forked, of (1--)2--4 terete segments, segments sometimes connate at base, in cross-section of 3--5 cells, one or more larger central cells surrounded by smaller cells, oil droplets present in all cells, 2-celled slime hairs with enlarged apical cell present in axils of leaves. Specialized asexual reproduction by caducous leaves or stems. Sexual condition dioicous, gametangia naked. Seta with foot, persistent, elongating prior to capsule maturation. Capsule erect, symmetric, lacking well-defined neck region, lacking stomates, dextrorsely spiralled at maturity, columella ephemeral, basifixed, not penetrating the archesporial tissue, peristome lacking, dehiscence by a longitudinal helical slit. Calyptra fugacious to rarely persistent, typically mitrate. Spores 3-radiate, slightly roughened to papillose.

Genera 1 (1 in the flora): North America, se Asia (including Borneo); cool, cold-temperate to Arctic-alpine oceanic climates.

Plants of this family were first collected in the Himalayas by J. D. Hooker and placed in the hepatic genus Lepidozia as L. ceratophylla by W. Mitten. For a long time, the consensus had been that it was a highly unusual liverwort with affinities to the Calobryales. Distinctive features include the erect shoots arising from a stolon , terete leaves, sometimes fused at or near the base and thus of 2--4 segments, naked lateral gametangia, slime cells, oil droplets, and chromosome numbers of n = 4 or 5. In 1993, sporophytes and antheridia were discovered in a population from Atka Island of the Aleutian Islands (D. K. Smith and P. G. Davison 1993). The sporophyte exhibits its affinity with the mosses, and is similar in some respects to sporophytes of the Andreaeopsida, by the columella, persistent seta, capsule that matures after seta elongation, dehiscence by a diagonal slit, and lack of elaters. R. M. Schuster (1997) suggested that gametophytically Takakia is more like a liverwort, and sporophytically more like a moss. The Japanese common name is perhaps most telling, literally translated as “puzzling moss."

SELECTED REFERENCES:

Hattori, S. 1963. Takakia of North Borneo (1). J. Jap. Bot. 38: 215--217. Hattori, S. and H. Inoue. 1958. Preliminary report on Takakia lepidozioides, J. Hattori Bot. Lab. 19: 133--137. Hattori, S., A. J. Sharp, M. Mizutani and Z. Iwatsuki. 1968. Takakia ceratophylla and T. lepidozioides of Pacific North America and a short history of the genus. Misc. Bryol. Lichenol. 4: 137--149. Hattori, S., Z. Iwatsuki, M. Mizutani and S. Inoue. 1974. Speciation of Takakia. J. Hattori Bot. Lab. 38: 115--121. Higuchi, M. and D. Zhang. 1998. Sporophytes of Takakia ceratophylla found in China. J. Hattori Bot. Lab. 84: 57--69. Renzaglia, K. S., K. D. McFarland and D. K. Smith. 1997. Anatomy and ultrastructure of the sporophyte of Takakia ceratophylla (Bryophyta). Amer. J. Bot. 84: 1337--1350. Schuster, R. M. 1997. On Takakia and the phylogenetic relationships of the Takakiales. Nova Hedwigia 64: 281--310. Smith, D. K. and P. G. Davison. 1993. Antheridia and sporophytes in Takakia ceratophylla (Mitt.) Grolle: evidence for reclassification among the mosses. J. Hattori Bot. Lab. 73: 263--271.

1. TAKAKIA S. Hattori & Inoue, J. Hattori Bot. Lab. 19: 133--137 * [For N. Takaki (1915--) who first collected the genus in Japan]

Plants small, bright green, in dense turfs. Stems short, 0.5--2 cm, erect, mostly unbranched or weakly sympodially branching with colorless branches arising at acute or right angles from the erect leafy stems. Leaves reduced proximally and widely spaced, distally more densely arranged and roughly 3-ranked or irregularly arranged, of 1--4 segments, erect or spreading. Sexual condition with antheridia lateral, elongate, orange-brown when mature, archegonia lateral and often orange-tinged, not halting subsequent stem growth. Seta 0.5--2.6 mm, straight and erect. Capsule, elongate-elliptic, 0.6--2.3 × 0.3--0.5 mm, green becoming brown. Spores 25--36 µm.

Species 2 (2 in the flora): nw North America, Asia (Borneo, China, India, Japan, Nepal).

1. Leaves essentially 3-ranked, mostly of 4 segments, connate at base, not caducous, in median cross-section segments with 2--5 inner large cells and 10--15 smaller thick-walled epidermal cells, distal portion of leafy shoots rigid, brittle and caducous, sporophytes infrequent; plants lacking a distinctive odor when dry . . . 1. Takakia ceratophylla

1. Leaves irregularly ranked, of (1--)2(3--4) segments , not or only occasionally connate at base, somewhat caducous, in median cross-section segments with 1--2 inner thin-walled cells and ca. 8 smaller thin-walled outer epidermal cells, distal portion of leafy shoots often lax, not caducous; sporophytes unknown; plants cinnamon-scented when dry. . . 2. Takakia lepidozioides

1. Takakia ceratophylla (Mitten) Grolle, Oesterr. Bot. Zeitschr. 110(4): 444, f. 1. 1963

Lepidozia ceratophylla Mitten, J. Linn. Soc. Bot. 5, 89: 128. 1861

Plants lacking distinctive odor when dry, distal portion of leafy shoot readily caducous. Stems in cross section with 2 layers of thicker walled epidermal cells, stoloniferous stems mainly subterranean. Leaves typically of thick-walled cells, in 4 segments, connate at base, cross section of each segment with 3--5 inner cells and 10--15 smaller outer epidermal cells, these outer cells small, 25 × 10 µm, regularly arranged. Slime hairs thick-walled. Capsule terminal, usually single.

Capsules mature late summer--early fall (July--Sept.). Uncommon to rare on moist soil and shaded banks, slopes and over rocks in tundra; 75--700 m; Alaska; Asia (China in Yunnan, India in Sikkim, Nepal).

This species appears to be somewhat tolerant of desiccation. Frequently it grows with other drought-tolerant bryophytes such as Andreaea and Gymnomitrion. The shoots are more rigid than those of T. lepidozioides and the leaf arrangement more regular. Rhizomatous shoots are predominantly subterranean.

2. Takakia lepidozioides S. Hattori & Inoue, J. Hattori Bot. Lab. 19: 137, f. 1-24. 1958

Plants with cinnamon-like odor when dry; distal part of leafy shoots not caducous. Stems in cross section usually with 1 layer of thicker walled epidermal cells; stoloniferous stems well developed and extensive above surface of substrate. Leaves typically of 2 segments, some solitary, occasionally of 3--4 segments, sometimes caducous, in cross section of thin-walled cells, in distal part of segment with single large central cell and 7--10 smaller outer cells, these 30--45 × 20--25 µm, irregularly arranged. Slime hairs thin-walled. Sporophytes unknown.

Uncommon on moist humus, in usually somewhat shaded habitats, over rocks or on banks, rock crevices, especially near waterfalls, but also on peaty banks in wetland slopes, humid coastal to subalpine and alpine elevations; 0--1000 m; BC; Alaska; Asia (Borneo, Japan, Nepal, Taiwan).

This species grows most frequently in highly humid or misty sites, often deeply shaded. Algae and cyanobacteria are frequent associates. The shoots are often lax and extensive rhizomatous shoots are conspicuous.