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Scaphophyllum Inoue, a monotypic segregate from Anastrophyllum (Spruce) Steph., agrees with Hattoria Schust. and Gottschelia Grolle in unlobed leaves, bilateral gymnoecia, collenchymatous cells and other criteria; it fails to fit in Jamesonielloideae or Lophozioideae because of the lack of a female bracteole. The canoe-shaped, deeply canaliculate and transverse leaves give it a wholly distinct aspect from other genera of Jungermanniaceae, sensu lato. The genus lacks clear links to others of that family and specifically to Jungermannioideae and must be retained in a separate subfamily, Scaphophylloideae Schust. The single species, S. speciosum (Horik.) Inoue is divided into the type subspecies speciosum with perianths armed below the apex with low tubercles and restricted to Taiwan, and subspecies villosum Schust., n. subsp., with perianth surfaces densely covered by long (to 300-325 ptm) rhizoid-like cilia and known only from Bhutan and Yunnan, China. In a pioneer work on Taiwanese Hepaticae, Horikawa (1934) published a large number of new taxa. Among them were two species that he assigned to Anastrophyllum (Spruce) Steph. One of the species, A. yakushimense Horik., was assigned to the new genus Hattoria Schust. (Schuster 1961). A detailed diagnosis and discussion are in Schuster (1961) and a good illustration appears in Inoue (1972). The other species, A. speciosum Horik., was assigned to Anastrophyllum subg. Aschizophyllum (nom. nudum) (Schuster 1961). Inoue (1966) elevated this taxon to generic status, as Scaphophyllum. When I published my study on Anastrophyllum sensu lato (to include Sphenolobus sensu Stephani 1898-1924), I was faced with a mass of taxa whose taxonomic provenance was difficult to establish. Some 10 genera had been confused by Stephani under his Anastrophyllum. Some taxa assigned to Anastrophyllum (including Sphenolobus) were segregated into Acrobolbus (A. acrophyllus (Hook. f. & Tayl.) Schust.), others to the new genus Andrewsianthus (A. puniceus (Nees) Schust. = Anastrophyllum puniceum Steph.), others to Hattoria Schust. (Hattoria yakushimensis (Horik.) Schust. = Anastrophyllum yakushimense Horik.), while still others could not be surely placed because of absence of adequate material. After 1961 I therefore abandoned any attempt to revise Anastrophyllum sensu Stephani. However, I emphasized that even after the entire-leaved Hattoria was segregated, two species of Anastrophyllum that have "the transverse leaf orientation of normal species of Anastrophyllum" but have "entire leaves," were, in essence, left in limbo. These species, A. schizopleurum (Spruce) Steph. and A. speciosum Horik., were soon assigned to new genera, the first to Gottschelia (Grolle 1968) and the second to Scaphophyllum Inoue. I had noted that this last species "had an areolation which is essentially unique." My hesitation in assigning it to an autonomous genus (and Aschizophyllum was not validated) was based on the fact that I had seen only a sterile fragment. The generic segregation, as Scaphophyllum, by Inoue (1966) was surely justified. Indeed, I soon thereafter showed that Scaphophyllum could not be retained in the same subfamily, Lophozioideae, with Anastrophyllum, and placed it in its own subfamily, Scaphophylloideae Schust. and, provisionally, also assigned here Hattoria Schust. (Schuster 1970). I was then uncertain of the placement of the latter genus, and (in the keys, Schuster 1970) keyed it with both the Scaphophylloideae and Jamesonielloideae. Indeed, the existence of isolated monotypes like Hattoria and Scaphophyllum was one of the reasons cited for broadening the concept of Jungermanniaceae to include both groups with lobed leaves (Lophozioideae) and with them unlobed (Jungermannioideae, Jamesonielloideae, and Scaphophylloideae, among others). The three genera with unlobed leaves; gynoecia devoid of a bracteole; and broadly ovate to ovatereniform, concave, vertically to semivertically inserted leaves are separable by the following key. 1. Leaves obliquely inserted throughout, dorsally extended to but not beyond stem midline; leaves broadly rotundate to rounded-reniform, widest near middle. Perianths smooth. Leaf margins never revolute. Stems ventrally smooth. Gemmae absent Hattoria Schust. 1. Leaves with dorsal half of insertion ? transverse (aside from decurrent strip in Scaphophyllum); leaves somewhat asymmetrically ovate to ovate to ovate-reniform, clearly widest in basal 0.25 and narrowed to rounded apex. Perianths toward apex 0007-2745/98/428-434$O. 85/O This content downloaded from 207.46.13.117 on Sun, 23 Oct 2016 04:35:01 UTC All use subject to http://about.jstor.org/terms 1998] SCHUSTER: SCAPHOPHYLLUM (JUNGERMANNIACEAE) 429 with cells elevated as tubercles or finger-like processes. Leaf margins revolute or not. Stems ventrally smooth or armed. Gemmae present or absent. -----------------2 2. Leaf insertion dorsally extended to but not beyond stem midline; leaf margins narrowly but conspicuously revolute. Stem ventrally armed with numerous longitudinal ridges/lamellae, many with teeth, or ending in cilia; rhizoids copiously developed along stem, forming felty or cottony masses; microphyllous stoloniform axes lacking. Stems without a defined, thick-walled cortex. Gemmae absent Scaphophyllum Inoue 2. Leaf insertion dorsally extended well beyond stem midline, the merophytes interlocking dorsally, leaf margins not revolute. Stems unarmed, the leafy stems virtually rhizoid-free, arising from a rhizoidous microphyllous system of axes. Stem with a 2-stratose cortex of uniformly thick-walled cells. Gemmae 1-celled, stellate ___ --------------------- Gottschelia Grolle On the following pages Scaphophyllum is given a critical appraisal, stimulated by study of fertile plants from Bhutan. Formal diagnoses of the genus are in Inoue (1966) and Schuster (1970); the discussion that follows supplements these diagnoses. SCAPHOPHYLLUM Inoue, Jour. Jap. Bot. 41(9): 266. 1966. Anastrophyllum subgenus Aschizophyllum Schust., Rev. Bryol. Lich6n. 30: 71. 1961. (nomen nudum). Scaphophyllum agrees with the otherwise very different Hattoria and Gottschelia in the vertical and almost transverse leaves, with anterior (dorsal) and posterior (ventral) leaf margins, both turned to the shoot apex; unlobed leaves; leaf cells with distinct (and in Gottschelia strongly nodose) trigones; long, noncompressed, distally pluriplicate perianths developed on leading shoot apices; and in the uniform lack of terminal branches. Gottschelia and Hattoria agree in the 4-stratose capsule wall (that of Scaphophyllum is unknown). In Schuster (1970) it is emphasized that "none of the three segregates from Anastrophyllum with unlobed leaves (Hattoria, Scaphophyllum and Gottschelia) can remain in the Lophozioideae"; furthermore, in spite of the similarities, the three are not at all closely interrelated. "Scaphophyllum is at once distinct in the overlapping, hyaline green, distichous, boat-shaped and strongly concave, stiffly laterally patent leaves. The plants are optimally dorsiventrally flattened, rather pellucid (only ventral leaf bases may be feebly reddish tinged), with the stem totally hidden both above and below; the similarity of the shoots when viewed postically and antically is almost unsurpassed in the Jungermanniales" (Schuster 1970). In these criteria Scaphophyllum is distinct from both Hattoria and Gottschelia. Inoue (1974), indeed, claimed that Gottschelia is "most closely allied" to Hattoria. All three genera agree not only in the unlobed leaves, but in gynoecia that are strictly distichous like vegetative sectors, and no t ace f a bracteole exists. In the several classifications I have adopted (Schuster 1966, 1979, 1984) a "Leitmotiv" has been the concept that many lines of evolution in the Jungermanniales led from erect taxa with triradial symmetry. Initially the third row of leaves (underleaves) underwent reduction and, eventually were lost-but in and near the gynoecia large to reduced appendages (bracteoles) from the ventral merophytes were retained. In the Jungermanniaceae sensu lato certain less derivative groups have ventral merophytes that remain well developed and produce distinct underleaves and, typically, even larger female bracteoles. However, in all Jungermanniaceae sensu amplo the gynoecium is already bilateral in the sense that the bracteole has suffered reduction vis a vis the bracts-unlike e.g., in the Cephaloziaceae, in which, even when vegetative sectors lack underleaves, gynoecia normally remain |
