A NEW BOWMANITEAN FRUCTIFICATION FROM THE PENNSYLVANIAN OF KANSAS

MAMAY, SERGIUS H. (U. S. Geological Survey, Washington, D. C.) A new bowmanitean fructification from the Pennsylvania of Kansas. Amer. Jour. Bot. 46(7): 530-536. Illus. 1959.-A new sphenophyllaceous fructification, Bowmanites moorei sp. nov., is described on the basis of coal ball petrifactions from the Fleming coal in southeastern Kansas. One of the simplest species of Bowmanites, B. moorei has only 3 sporophylls in a whorl. Each sporophyll has 3 lobes, the median one fertile, the 2 lateral ones sterile. Each fertile lobe subtends 2 sporangia, resulting in 6 sporangia in a whorl. The sporangia are inverted, being distally attached to separate sporangiophores that arise in pairs, in axillary positions. The sporangial epidermis and epidermis of the lower surfaces of the sporangiophores are characterized by relatively large, thick-walled cells. The spores are small, spherical, and trilete, without distinctive ornamentation of the exine. B. moorei adds to the morphological variation known in Bowmanites, but contributes little toward a phylogenetic interpretation of this morphologically complex genus. THE PALEOZOIC genus Sphenophyllum, particularly abundant in Pennsylvanian floras, is characterized in part by strobilar fructifications of varying complexity, which are placed in the organ genus Bowmanites when found detached. Bowmanites was monographed in 1943 by Hoskins and Cross; as emended by them, the genus contained 18 species which, in spite of their considerable morphological diversity, have sufficiently important characters in common to constitute a single genus. The specimens discussed in this paper fall within Hoskins' and Cross' circumscription of Bowmanites but are distinct enough to warrant description as a new species. Interest in the new species, B. moorei, lies in its simple construction, which contrasts sharply with the complexity of previously described species such as B. fertilis (Scott) Hoskins and Cross or B. trisporangiatus Hoskins and Cross. SOURCE, AGE, AND PREPARATION OF MATERIAL.Two incomplete cones were found in coal balls of Des Moines age, from strip pits of the Pittsburg and Midway Coal Company in Cherokee County, Kansas. One specimen (U.S.N.M. 40934) was first exposed by a nearly transverse saw cut through a whorl of sporangia. Additional preparation showed this to be a terminal cone fragment about 1 cm. long; since it was the more complete of the 2 specimens it was designated the holotype. About half the length of the holotype was used in peel preparation of a series of transverse sections. The series was started at the base of the specimen and 1 Received for publication February 17, 1959. Publication authorized by the Director, U. S. Geological Survey. 2 U. S. Geological Survey, Washington 25, D. C. I wish to express appreciation to Mrs. Elinor Stromberg, U. S. Geological Survey, for preparation of fig. 17, and to Mr. N. W. Shupe, U. S. Geological Survey, for preparation of the photographic illustrations. stopped at the median plane of the second sporangial whorl above the basal one. This series clearly illustrates the basic plan of the nodal complex. The remainder of the specimen was used in preparation of longitudinal sections, which clarify such features as length of internodes and attitudes of the appendages. The holotype was partly fusinized, but generally the preservation was satisfactory and the parts sufficiently undistorted to permit a reasonably accurate reconstruction of the organization of a whorl (fig. 17). The paratype (U.S.N.M. 40935) was less complete than the holotype, but somewhat better preserved. It was also sectioned serially and has provided fine details such as cellular differentiation in the sporangial walls and sporangiophores. DESCRIPTION.-General.-Bowmanites moorei is a small cone of unknown length, with a greatest diameter of about 4.0 mm., consisting of directly superposed whorls of appendages. Each whorl consists of 3 units, or sporophylls, which are laterally coalescent to form a sporophyll disc. Each unit contains a median fertile lobe that subtends a pair of sporangia, and 2 lateral sterile lobes. The tips of the lobes are bent upward but are not long enough to overlap the next higher sporophyll disc. The 2 sporangia of each fertile lobe arise from axillary positions, each being borne on a separate sporangiophore and assuming a recurved or inverted attitude., The spores are small, spherical, trilete, and without distinctive ornamentation. The cone axis and its vascularization.-The axis is terete in cross section and averages about 1.0 mm. in diameter, except in the upper parts of the internodes, where appression with the sporangia imparts to the axis a hexagonal outline, about 0.75 mm. across (fig. 5). The axial epidermis has no distinctive features. The cortex is a broad, homogeneous tissue of small, vertically elongate, thinwalled parenchymatous cells.