BFNA Title: Geocalycaceae
XX. GEOCALYCACEAE Klinggraff
John J. Engel
Plants in mats or turfs, with branches ventral-intercalary in axils of underleaves, without flagella. Leaves alternate , succubous, shallowly 2-lobed, entire; underleaves large, 2-lobed. Rhizoids in fascicles from stem at base of underleaves but in some species becoming scattered on ventral surface of stem. Specialized asexual reproduction absent [gemmae]. Androecia typically on abbreviated, determinate, ventral-intercalary, distinctly spicate branches. Gynoecium on a short ventral branch, without subfloral branches. Perianth absent, perigynium a deep marsupium.
Genera 1, species 4 (1 in the flora): North America, Europe, Asia, Africa (Reunion Island), Pacific Islands (New Caledonia, New Zealand).
The monogeneric family Geocalycaceae is distinguished by the opaque, yellow to whitish green leaves with a roughened or papillose cell surface, ventral-intercalary branches originating from axils of underleaves, succubously inserted 2-fid leaves, large, conspicuous, deeply 2-fid underleaves, and autoicous plants that develop Calypogeia-type marsupia, these tubular and strongly rhizoidous, with a true calyptra present, originating about half way up the marsupium
1. GEOCALYX Nees, Naturg. Eur. Leberm. 1: 97. 1833 * [Greek gaea (earth), and kalyx (fruit or flower cover), alluding to the buried marsupium]
Plants loosely prostrate; Frullania-type branches very rare. Leaves ovate‑rectangular, 2-lobed to 0.15--0.35, the lobes acute; margins entire. Cells with surface papillose. Underleaves conspicuous, free or weakly connate on 1 side, ovate-lanceolate to oblong, 2-fid from ca. 0.65 to nearly the base, the lobes parallel, linear‑lanceolate, entire. Sexual condition autoicous. Marsupium tubular, strongly rhizoidous, summit with small involucral bractlets. Sporophyte with long seta, capsule cylindric, dehiscing by four valves, walls 2-stratose, outer walls with nodular thickenings. Spores faintly papillose or vermiculate.
Species 4 (1 in the flora): North America, Europe, Asia, Africa, Pacific Islands (including New Zealand), Australia.
1. Geocalyx graveolens (Schrader) Nees, Naturg. Eur. Leberm. 2: 397. 1836
Jungermannia graveolens Schrader, Syst. Samml. Krypt. Gewächse 2: 6. 1797
Plants yellow- to whitish or milky-green, medium in size, to 1.5 mm wide. Branches rare. Stems with epidermis weakly differentiated, in a single layer of slightly smaller, weakly firm-walled cells. Rhizoids hyaline, long for plant size. Leaves ± plane to weakly and broadly convex, with apices occasionally deflexed, the leaves horizontal, widely spreading, moderately imbricate, the insertion line nearly horizontal and ± straight throughout, sometimes becoming feebly curved at the extreme ventral end, the insertion line not reaching stem midline dorsally, leaving a leaf-free strip a few to several cells wide, the leaves oblong-ovate, 2-lobed to 0.25--0.35; lobes usually subequal, often apiculate; sinus variable, angular to rounded at the base; dorsal margin ± straight, the base short decurrent; ventral margin moderately and evenly arched. Cells opaque, the walls thin, trigones lacking or small and concave-sided to medium and straight-sided, the median cells 24--34 x 16--26 /um. Oil-bodies 6--10(--12) per median cell, only 2--6 per cell at leaf apex, golden yellow to pale brownish, appearing finely granular-papillose, subspherical to more often ovoid, 5--8 x 3.5--4.5 /um, to 10 x 7 /um. Underleaves about as broad as stem, free, loosely appressed to stem, narrowly oblong to elongate subrectangular, 2-fid to (0.5--)0.7--0.8; lobes linear-lanceolate, parallel to feebly divergent; lamina margins entire. Sexual condition with male and female branches in close proximity. Androecia with bracts in 4--8 pairs, closely imbricate, ventricose-cucullate, 2-lobed, the dorsal margin with an incurved tooth toward base. Gynoecium with small scale-like bracts. Seta to 3 cm, with 16--20 rows of outer cells surrounding an inner core of ca. 30 somewhat smaller cells. Capsule short cylindric, the wall with outer and inner layers of more or less equal thickness or the inner layer a little less thick; outer layer of cells more or less regularly rectangular, the radial walls with nodule-like thickenings mostly on longitudinal walls, occasionally on transverse walls, the longitudinal and often transverse walls with slightly thickened continuous sheets of wall material; inner layer of cells rectangular, often long and narrowly so, with semiannular bands abundant, the bands sporadically non-pigmented in median portion, sporadically incomplete, sometimes forked. Spores (10--)11--12 /um, yellow to reddish brown, faintly papillose, the papillae rounded and not coalescing. Elaters bispiral, slightly tortuous, ca. 8 /um wide.
Over humus and soil, along streams and on decaying wood. Miquelon; Alta.,B.C., N.B., Nfdl. and Labrador; N.W.T., N.S., Ont., Que., Yukon; Alaska, Calif., Conn. Del., D.C., Idaho, Ill., Ind., Kans., Ky., Maine, Md., Mass., Mich., Minn., N.H., N.J., N.Y., N.C., Oreg., Pa., R.I., Tenn., Vt., Va., Wash., W.Va., Wis.; Europe, Asia (Caucasus, Siberia, Japan); Atlantic Islands (Azores).
Geocalyx graveolens is a circumboreal species, which in North America is regionally abundant in spruce-fir forests, moving south into mixed hardwood forests. It is distinctive in the yellow-green, opaque quality of the leaves. The color along with the regularly 2-lobed leaves and narrow, deeply 2-fid underleaves are enough to confidently determine this liverwort in the field. When fresh, plants are pleasantly aromatic. The traits of oil bodies are as given by R. M. Schuster (1980).