BFNA Title: Sphaerocarpaceae
Stephen L. Timme
Plants dioicous, strongly dorsiventally flattened, with alternate, unlobed wings (lobes, leaf scales). Branching symmetrically pseudodichotomous or simple. Rhizoids present, unbranched, smooth-walled, colorless, arising at the base or near the base of the ventral surface or along the costal region. Ventral scales absent. Cells thin-walled and lacking noticeable oil bodies. Gametangia developing acropetally, one per involucre. Antheridia and archegonia developing in 1-stratose, somewhat bottle-shaped or tubular involucres, generally scattered over the dorsal surface. Sporangia with a very short or essentially lacking seta. Capsule cleistocarpic, 1-stratose, nurse cells (sterile cells) present; elaters absent. Spores remaining in tetrads or separating at maturity.
Genera 2 (2 in the flora): on soil in subtropical to temperate areas; North America, South America, Europe, Africa, Australia.
SELECTED REFERENCE Shuster, R. M. 1992. The Hepaticae and Anthocerotae of North America, East of the Hundredth Meridian. Chicago.
1. SPHAEROCARPOS Boehmer, Nova Plant. Genera 4, pl. 3. 1729 * [Greek, sphaero + carpos, globose fruit, for shape of capsule]
Stephen L. Timme
Plants as short-lived annuals, heterothallic, hyaline green, light green to bright green, sometimes becoming reddish or purplish, 2- to multistratose in the median region, grading to 1-stratose and entire lobes (wings). Antheridial plants generally 0.1--0.3 times smaller than the archegonial. Archgonial plants 2--15 mm in diameter; lobes 1-stratose, not divided or lobed, generally succubous. Cells lacking trigones, quadrate to hexagonal. Sporangia ovoid. Seta very short, not elongating, of 4 cell rows. Spores large, spore wall reticulate or not, faces aerolate; aerole with or without tubercles, cristatae, lamellae, crenulae or spines.
Species 8--10 (6 in flora): terrestrial specialists almost always occupying disturbed or temporary habitats; nearly worldwide, but disjunct, sporatic and localized throughout range; North America, South America, Europe, s Africa, s Australia.
With species of this genus, the capsules mature February through May.
SELECTED REFERENCES Campbell, D. H. 1940. The Evolution of Land Plants. Stanford, Calif. Crandall-Stotler, B. and R. E. Stotler. 2000. Morphology and classification of the Marchantiophyta. In: Bryophyte Biology, A. Jonathan Shaw and B. Goffinet, eds. Cambridge Univ. Press, New York. Pp. 21-70. Frye, T. C. and L. Clark. 1937. Hepaticae of North America. Univ. Wash. Publ. Biol. 6: 1--162. Haynes, C. C. 1910. Sphaerocarpos hians sp. nov., with a revision of the genus and illustrations of the species. Bull. Torrey Bot. Club 37: 215--230. McGregor, R. L. 1955. Taxonomy and ecology of Kansas Hepaticae. Univ. Kans. Sci. Bull. 37: 55--141. Proskauer, J. 1948. The Sphaerocarpales of South Africa. J.. S. Africa Bot. 21: 63--75. Schuster, R. M. 1992. The Hepaticae and Anthocerotae of North America, East of the Hundredth Meridian. Chicago. Schuster, R. M. 1984. Evolution, Phylogeny and Classification of the Hepaticae. In: R. M. Schuster, ed. New Manual of Bryology, Vol. 2, pp. 892--1070. Nichinan, Miyazaki, Japan.
1. Spores separating at maturity.
2. Spores less than 85 µm in diameter, pale yellow to yellowish-brown; archegonial involucres less than 1.4 mm . . . 1. Sphaerocarpos cristatus
2. Spores 85 µm or greater, blackish-brown to yellowish-brown; archegonial involucres 1.5 mm or longer; southeastern U.S.A. . . .2. Sphaerocarpos donnellii
1. Spores remaining in tetrads at maturity.
3. Spore surface with thickenings in parallel or nearly parallel lines, occasionally with reticulations . . .3. Sphaerocarpos drewei
3. Spore surface with thickenings definitely reticulate, not in parallel lines.
4. Apex of the archegonial involucre with a large ostiole greater than 50 µm, generally as wide as the medial portion of the involucre; involucres tubular to ovoid; spore tetrads less than 90 µm at maturity . . . 4. Sphaerocarpos hians
4. Apex of the archegonial involucre with a small ostiole less than 140 µm, mouth contracted; involucres flask-shaped, obpyriform, clavate, obovoid to subglobose; spore tetrads generally more than 90 µm at maturity.
5. Tetrads spinose in profile, less than 135 µm at maturity . . . .5. Sphaerocarpos michelii
5. Tetrads crenulate in profile, greater than 135 µm at maturity . . . 6. Spaherocarpos texanus
1. Sphaerocarpos cristatus M. A. Howe, Mem. Torrey Bot. Club 7: 66. 1899
Archegonial plants 2.5--8.5 mm in diameter; lobes nearly orbicular. Involucres 0.8--1.3 mm, densely aggregated, nearly obscuring the thallus, cylindrical to obovoid, rounded to the apex. Antheridial plants to 2 mm long, cuneate, often bifurcate. lobes ovate to oblong, involucres 500--585 µm high, bottle-shaped, expanded at the base and abruptly narrowed and becoming tubular toward the apex. Sporangia 500 µm or more. Spores of tetrads separating before maturity, yellowish to yellowish-brown, 48--83 µm in diameter, somewhat aerolate, mostly cristate, appearing to radiate from near the middle, lacking medial tubercle, ridges sinuous to slightly crenulate, 3.8--7 µm high, appearing to radiate from the central part of the face, slightly anastomosing, with 1--6 aerolae across the face.
On soil; low elevations; Calif.
Rare, known only from California in Alameda, Tulare, San Joaquin, and Santa Clara counties.
2. Sphaerocarpos donnellii Austin, Bull. Torrey Bot. Club 6: 157. 1877
Sphaerocarpos terrestris Underwood & Cook, Hep. Amer. no. 61 (Exsic.). 1890
Archegonial plants 8--10 × 4-7 mm, solitary or forming mats, lobes divided to the costa, oblong to obcuneate, sinuous, marginal cells ca. 30 × 68 µm; involucres 1.5--2.4 mm high, tubular, ovoid, ellipsoid to pyrifrom, truncate at the apex, orifice rounded. Antheridial plants 2.5--4 mm in diameter, lobes divided to the costa or nearly so, cuneiform to obdeltoid, sinuous; involucres flask-shaped, 0.5-1.1 mm high. Sporangia 700--855 µm. Spores of tetrad separating at maturity, 85--135 µm, nearly tetrahedral, yellowish, dark brown to blackish-brown, basal margin lobed and dentate, aerolae 3--4 across the face, surface granulate, 13--27 µm in diameter, ridges generally appearing wrinkled, blunt to spinose at the intersections and thus appearing spinose or nearly so in profile, central tubercle generally present in each aerola, to 24 µm high.
Damp sandy soil, muddy shores, organic muck over coral limestone; low elevations; Fl., Ga., Miss., S.C, Va.
This species is very localized and restricted to the Southeastern Coastal Plain.
3. Sphaerocarpos drewii Wigglesworth, Univ. Calif. Pubs. Bot. 16: 129. 1929
Archegonial plants 1--1.5 mm long, bifurcate, sometimes with an elongated branch, becoming reddish or purplish at the margins, lobes wedge-shaped, ca. 550 µm wide with quadrate marginal cells; involucres cylindric to obovate, 0.5--1.1 mm high, crowded over the thallus and nearly obsuring it. Antheridal plants ca. 1--1.5 mm long, lobes somewhat wedge-shaped; marginal cells isodiametric, involucres flask-shaped, to 365 µm high. Sporangium 335--595 µm. Spores remaining in tetrads at maturity, 65--155 µm, brown to dark-brown; lamellae granulate and occasionally lobed, running parallel to one another or nearly so, occasionally branching, lacking tubercles; not reticulate.
Soil; low elevations; known only from Calif. (San Diego county).
This and the following species are the rarest of the North American Sphaerocarpos.
4. Sphaerocarpos hians Haynes, Bull. Torr. Bot. Club 37: 225. 1910
Archegonial plants 3.5--7 mm in diameter, growing in isolated tufts, lobes crispate and somewhat ascending, involucres 1--2.5 mm high, tubular, ovoid, to obovate, generally flaring at the apex; orifice large, wider than or as wide as the involucral apex or nearly so. Antheridial plants 1.8--2.1 mm in diameter, cuneate, oblong to orbicular, involucres 235--415 µm high, greenish, becoming purplish with age, vase-shaped, narrowing toward the apex or obovate. Sporangia 570--590 µm. Spores in permanent tetrads at maturity, 62--85 µm, yellowish-brown, cristate, ridges to 5 µm high, forming reticulae or in parallel lines, crenulate to tuberculate in profile, areolae present, 4--6 across the face, sometimes with 1--2 tubercules.
Damp clay or alluvial soils; low elevations; Idaho, Oreg., Wash.
This species and S. drewii are the rarest of North American Sphaerocarpos.
5. Sphaerocarpos michelii Bellardi, App. ad Fl. Pedem, 1792; Mem. Acad. Roy. Sci.
Turin 5: 258. 1793
Sphaerocarpos sphaerocarpus Howe
Archegonial plants 8--13 mm in diameter, lobes ovate, involucres generally obscuring the thallus, 1.3--2.6 mm high, nearly obovoid, clavate, tubular, pyriform to nearly globose, orifice small. Antheridial plants ca. 1 mm in diameter, lobes generally arching over the involucres, involucres 250--330 µm high. Sporangia 735--760 µm. Spores remaining in tetrads, 80--125 µm, brownish to nearly black at maturity, aerolae 6--9 across the face, each ca. 12--20 µm in diameter, occasionally with a central tubercle, ridges at the junctions spinose, 7--12 µm high.
Damp soil of fallow fields, sandy soil of tall-grass prairies, and soils of seasonal flooding; Kan., Tex., Mo. (Howell County), S.C. (Chester County), Va. (York County); South America (Argentina); Europe; Atlantic Islands (Canary Islands).
This species is found in in eastern Kansas and a few counties in Texas as scattered and isolated populations, while being rare elsewhere. It is very similar to S. texanus.
6. Sphaerocarpos texanus Austin, Bull. Torr. Bot. Club 6: 158, 1877
Sphaerocarpos berterii Austin; S. californicus Austin; S. michelii var. californicus Underwood
Archegonial plants 6--15 mm in diameter, nearly orbicular to cuneate; bright green to hyaline green, central axis 2- to multistratose, lobes 1-stratose, crispate, obovate to slightly obdeltoid, apex rounded, involucres sessile, generally 2--2.6 mm high, obpyriform, fusiform, ellipsoid to slightly clavate, contracted to the orifice, mouth very small. Antheridial plants 2--6 mm in diameter, green to nearly hyaline green, lobes cuneiform to obdeltoid, involucres 260--360 µm high, crowded over the dorsal surface, orbicular, oblong to flask-shaped. Sporangia ca. 620--700 µm. Spores permanently united in tetrads, yellowish-brown to dark-brown, 115--175 µm, granulate to areolate, areolae 5--7 across the face, lacking a median tubercle, reticulations 15--30 µm in diameter, crenulate or not.
Soils of disturbed areas and areas of seasonal flooding; Ala., Ark., Calif., Fla., Ga., Ill., Kans., Ky., La., Miss., Mo., N.C., Okla., Oreg., S.C., Tenn., Tex., Va., Wash.; South America (Uruguay); s and c Europe, n Africa; Atlantic Islands (Canary Islands); Australia.
This is the most widespread and commonest species of Sphaerocarpos. It is considered weedy because of its apparent habitat preference. Sphaerocarpos texanus has not been reported from the Intermontane region of North America, which includes Arizona, Colorado, Utah, Idaho, Wyoming, Nevada, New Mexico, Idaho, and Montana, or from the very northcentral and northeastern regions of the flora area.