Ann. Bot. Fennici 36: 271–283 ISSN 0003-3847 Helsinki 14 December 1999 © Finnish Zoological and Botanical Publishing Board 1999

Circumscription of the family , with segregation of the new family Diplophyllaceae (Hepaticae)

Alexey D. Potemkin

Potemkin, A. D., Department of Lichenology and Bryology, V. L. Komarov Botanical Institute, 2 Prof. Popov Street, St. Petersburg, 197376 Russia Received 4 May 1999, accepted 2 September 1999

Potemkin, A. D. 1999: Circumscription of the family Scapaniaceae, with segregation of the new family Diplophyllaceae (Hepaticae). — Ann. Bot. Fennici 36: 271–283. On the basis of phylogenetic analysis, the family Scapaniaceae Mig. is emended to include only the genus (Dumort.) Dumort. emend. Potemkin. The genus Macro- diplophyllum (H. Buch) Perss. is recognized as a subgenus in Scapania. The new com- binations Scapania subgenus Macrodiplophyllum (H. Buch) Potemkin and Scapania plicata (Lindb.) Potemkin are provided. A new family, Diplophyllaceae Potemkin, with two genera, Diplophyllum (Dumort.) Dumort. and H. Buch, is segregated from the Scapaniaceae as a group of different origins resulting in a different morphology. Douinia is distinguished as a genus derived from Diplophyllum and its rank as a sub- family is rejected. The distinctive characters of Delavayella Steph. are discussed. Seg- regation of Delavayellaceae R.M. Schust. and Blepharidophyllaceae (R.M. Schust.) R.M. Schust. from the Scapaniaceae is supported. Key words: Blepharidophyllaceae, Blepharidophyllum, Delavayella, Delavayellaceae, Diplophyllaceae, Diplophyllum, Douinia, evolution, hepatics, Macrodiplophyllum, Sca- pania, Scapaniaceae,

INTRODUCTION lies, Blepharidophyllaceae (R.M. Schust.) R.M. Schust. and Delavayellaceae R.M. Schust., and The family Scapaniaceae Mig. has in recent lit- that resulted in the delimitation of the Scapania- erature included two to four subfamilies. Grolle ceae with two subfamilies, Scapanioideae, with (1983) recognized within it four subfamilies, i.e. the genera Scapania (Dumort.) Dumort., Diplo- Scapanioideae, Douinioideae R.M. Schust., Ble- phyllum (Dumort.) Dumort., and Macrodiplophyl- pharidophylloideae R.M. Schust., and Delavayel- lum (H. Buch) Perss. (mostly distinguished as a loideae (R.M. Schust.) Grolle. Schuster (1961, subgenus of Diplophyllum) and Douinioideae, 1979, 1983) distinguished two of them as fami- with only Douinia H. Buch. 272 Potemkin • ANN. BOT. FENNICI 36 (1999)

Phylogenetic study of the genus Scapania led I know, has never been placed as the basal genus me to elucidate the relationships of the major enti- of Scapaniaceae. The known interpretations of re- ties of Scapaniaceae with its type genus, Scapania. lationships of Scapaniaceae appear to be based Analysis of these relationships is provided below. on the concept of gradual transformation of the lophozioid ± indefinite keel and inflated perianth into the acute keel and compressed perianth of TAXONOMIC DISCUSSION Scapania. Apparently, on this basis Scapania usu- ally follows Diplophyllum in virtually all hand- Scapania books. I consider both genera as efficiently spe- cialized in different ways. The initial point for phylogenetic analysis of Sca- Accepting in general the system of - paniaceae was definition of the basal genus. I con- ceae suggested by Schuster (1951), with the sec- sider Scapania as the basal genus of the family, tion Kunzeanae R.M. Schust. (i.e. Orthocaulis) since it demonstrates a greater diversity of evolu- of Orthocaulis (H. Buch) R.M. Schust. as the ba- tionary potential (Potemkin 1998). In that paper I sal group, I distinguish and Anastro- assumed Scapania as a genus derived from the phyllum as rather advanced groups to evolve from ancestral type intermediate between the family Scapania. Jungermanniaceae Rchb. (subfam. Lophozioideae kunzeana (Huebener) Müll. Macvicar) and the family Gymnomitriaceae H. Frib. is exceedingly variabile in width of ventral Klinggr. A position close to the Gymnomitriaceae merophyte, cuticle papillosity, leaf shape (occur- was concluded because of discovery of 2–3-spi- rence of arctic forms with bilobed almost condu- ral elaters and 2–3-stratose capsule walls in Scapa- plicate leaves and reduced underleaves is remark- nia praetervisa Meyl. However, this may be not a able), its 3–4-stratose capsule wall combined with sign of an ancestral type but a result of adaptation many other characters, to convince me that Sca- to harsh ecological conditions of growth on bare pania is a genus derived from an ancestor related soil in an arctic and alpine environment. A simi- to this species. Barbilophozia kunzeana itself, lar structure of elaters is known for Nardia brei- however, is different from Scapania in the some- dleri (Limpr.) Lindb., Prasanthus jamalicus Po- what angulate gemmae, inflated perianths, mostly temkin, Marsupella alpina (Limpr.) Bern., M. bre- regular development of underleaves, and some vissima (Dumort.) Grolle, M. sparsifolia (Lindb.) other characters. I think the gemma shape was Dumort., and some other species of Marsupella apparently not strongly fixed at the base of the Dumort., mostly characteristic of “difficult”, bare evolution of Lophozioideae, and this lead to ap- soil habitats. These features of the elaters were pearance of ovoid gemmae in two evolutionary lin- also observed in Scapania scandica (Arnell & H. eages of Lophozioideae (Lophozia heterocolpos Buch) Macvicar var. argutedentata H. Buch (Po- (Hartm.) M. Howe and L. capitata (Hook.) Macoun temkin 1993) and S. spitsbergensis (Lindb.) Müll. s. lato) and in Scapania. On the basis of the high Frib. (Potemkin 1994). The complete absence of plasticity of the Barbilophozia kunzeana-like an- gemmae in all known gymnomitrioid taxa sup- cestor, the idea of perianth compression correlated ports the assumption of ecologically induced par- with leaf keel development seems possible. allelism of elater structure. On this basis a lopho- Analysis of the present distribution of Scapa- zioid origin of Scapania seems most probable. nia shows that the highest endemism and richest Relationships between Scapaniaceae and Lo- representation of diverse taxonomic groups is in phoziaceae have repeatedly been suggested (e.g., SE Asia. The few species known from the South- Buch 1928, Schuster 1951, 1974, Kitagawa 1965). ern Hemisphere (except the highly advanced sub- These authors considered the genera Tritomaria genus Macroscapania R.M. Schust.) are more or Loeske and (Spruce) Steph. less advanced representatives of the northern (Schuster 1951) as closest to Scapaniaceae. How- groups. Therefore Scapania is considered as a ever, before Potemkin (1998), Scapania, as far as genus of Laurasian origin. ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 273

Macrodiplophyllum pania sphaerifera to elucidate a possible evolu- tion of Macrodiplophyllum through S. sphaerife- The genus Macrodiplophyllum (H. Buch) Perss. ra-Macrodiplophyllum microdontum “bridge”. (≡ Diplophyllum subgen. Macrodiplophyllum H. Scapania sphaerifera resembles M. microdontum Buch in most modern treatments) is considered in (1) ± sheathing and rounded leaf bases, (2) acute to be closest to Scapania. It includes three spe- distal keel sectors, (3) shape of ventral lobes, (4) cies, M. imbricatum (M. Howe) Perss., M. micro- spinous terminal cells of marginal leaf teeth and dontum (Mitt.) Perss., and M. plicatum (Lindb.) distribution of teeth to the leaf base, (5) leaf areola- Perss., occurring mostly in the area of the North tion, (6) cuticle structure, (7) multicellular gem- Pacific Arc. All species of Macrodiplophyllum mae with intersecting internal walls, (8) pattern have a scapanioid leaf dentition (if any), areola- of modification of gemmiparous leaves with char- tion, and insertion (short decurrent to arcuate), as acteristic elongation of marginal cells, (9) stem well as ventral intercalary branching (character- anatomy with frequent occurrence of ventral my- istic of many Asian Scapania), that provide rea- corrhiza infection, and (10) pluriplicate perianths son to associate them with Scapania rather than slightly contracted to the mouth, with the mouth with Diplophyllum. lobulate-ciliate (cf. Figs. 1 and 2; Buch 1928: fig. VI, Distinctions of Macrodiplophyllum imbrica- Konstantinova & Potemkin 1994: fig. 2). Moreo- tum, M. microdontum, and M. plicatum are not ver, they have similar ecological requirements and equivalent. If M. microdontum has a ± scapanioid were collected together in the Verkhoyansky appearance and stands close to S. sphaerifera H. Range (9.VII.1998 Akimova, LE). The character Buch & Tuom., the two other species resemble a of special significance connecting S. sphaerifera robust Diplophyllum due to the leaf bases long and M. microdontum is the 3–4-celled gemmae sheathing the stem, and more narrow lingulate fal- with intersecting internal walls. Regular produc- cate ventral lobes. tion of multicellular gemmae with intersecting I hypothesize evolution of Macrodiplophyllum internal walls is known within Scapaniaceae only through Scapania sphaerifera-Macrodiplophyl- in these species. lum microdontum “bridge” (which is considered The principal distinctions of Macrodiplophyl- below). Macrodiplophyllum microdontum is a spe- lum microdontum from Scapania sphaerifera are cies with a less specialized “macrodiplophylloid” (1) ± falcate ventral and particularly dorsal lobes, morphology, a broader range and probably a great- (2) stronger arched comissura, greater sheathing er ecological amplitude than the two other spe- of the stem, (3) more slightly flattened and very cies. The morphological hiatus between M. micro- regularly plicate perianths (vs. more flattened, ir- dontum and the M. plicatum-imbricatum complex regularly plicate perianths of S. sphaerifera (cf. resulted from suppression in the latter of the ba- Buch 1928: fig. VI, Konstantinova & Potemkin sal leaf dentition and cuticle papillosity charac- 1994: fig. 2), (4) ability to develop very crowded, teristic of M. microdontum, as well as from their branched, long ciliate lobules of the perianth leaf bases longer sheathing the stem and more mouth, (5) shorter, at base mostly 1-celled mar- narrow lingulate falcate ventral lobes. Suppres- ginal teeth of leaves, (6) predominantly angulate sion of the dentition and papillosity has probably (vs. sphaeric) gemmae, and (7) occurrence of in- resulted from adaptations of these species to hu- termediate thickenings of basal leaf cells. All of mid conditions in rock crevices and similar sites these distinctions, however, may be explained as in oceanic areas of the North Pacific Arc. Enhance- ecologically induced and genetically stabilized ment of the diplophylloid morphology (formation modifications of the character expressions. In fact, of longer sheathing leaf bases particularly) seems characters that distinguish Macrodiplophyllum to be a device to compensate the suppression of from Scapania are not more significant than those basal tooth distribution. of the subgenera Plicaticalyx (Müll. Frib.) H. Buch It is necessary to define the distinctions be- emend. Potemkin (1999), Ascapania Grolle and tween Macrodiplophyllum microdontum and Sca- Scapania sensu Potemkin 1998 of the genus Sca- 274 Potemkin • ANN. BOT. FENNICI 36 (1999)

Fig. 1. Scapania sphaerif- era H. Buch & Tuom. — A: Gemmiparous area along inner margin of ventral lobe. — B, J: Selected gemmae of different shapes. — C: Shoot sec- tor, antical aspect. — D: Apex of ventral lobe with marked papillae. — E: Ba- sal sector of ventral lobe margin. — F: Stem cross section, lateral sector. — G: Leaf base cross sec- tion. — H: Leaf keel sec- tion, distally. — I: Lobule of immature perianth mouth. — A–G, I drawn from 15.VIII.1989 Ka- zanovsky (LE); H, J from 9.VII.1998 Akimova (LE). — Scale bars: a = 800 µm (C); b = 50 µm (A, B, D–J). pania. Engel & Smith Merrill 1998). Occurrence of some The distinctions of Macrodiplophyllum and species in different habitats appears to be second- Diplophyllum appear to be considerably more sig- ary. So, D. taxifolium (Wahlenb.) Dumort. usu- nificant than those of Macrodiplophyllum and Sca- ally grows on bare mineral soil, but it behaves as pania. They are considered under Diplophyllum. a typical species of swampy tundras in the Seward Peninsula, Arctic Alaska (Potemkin, unpubl.). Di- plophyllum obtusifolium (Hook.) Dumort. rarely Diplophyllum s. str. grows on rotten wood (Smith 1990). Despite a considerable overlap of variability The morphology of Diplophyllum species is an in many separate characters of Diplophyllum, Sca- expression of their adaptations to more xeric habi- pania and Macrodiplophyllum, the following fea- tats in comparison with those of Macrodiplophyl- tures of Diplophyllum, when taken together, re- lum and most species of Scapania. Diplophyllum main very distinctive: (1) transversely inserted is primarily restricted to bare mineral soil and/or leaves, (2) mostly ± small leaf cells, (3) ± evenly rocks (Amakawa & Hattori 1955, Schuster 1974, thick- to thin-walled cells without sharply defined ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 275

Fig. 2. Macrodiplophyllum microdontum (Mitt.) Perss. — A: Basal sector of ventral lobe margin. — B: Apex of ventral lobe with marked papillae. — C: Selected gemmae of different shapes. — D: Gemmiparous area along outer margin of ventral lobe with marked papillae. — E: Shoot sector, antical aspect. — F: Leaf base and stem cross section. — G: Leaf keel section, distally. — H: Lobule of immature perianth mouth. — All drawn from 8.VIII.1997 Ignatov (LE). — Scale bars: a = 50 µm (H); b = 800 µm (E); c = 50 µm (D); d = 50 µm (A–C, F, G). 276 Potemkin • ANN. BOT. FENNICI 36 (1999) trigones, (4) presence of a definite marginal bor- compiled by Engel and Smith Merrill (1998), der, (5) leaf margin chiefly finely densely crenu- show that in the Southern Hemisphere and sub- late to denticulate due to regularly projected walls equatorial areas the genus has considerably more of neighbor marginal cells, (6) with stronger de- species than in the Northern Hemisphere (16 vs. veloped projections to leaf bases (Fig. 3A, C, G, I 8 respectively), and these are chiefly very local and K), (7) development of strongly elongated ba- endemics. Maximal level of endemism is known sal leaf cells, (8) tending to form a vittate area for the territory of New Zealand, Tasmania and (Fig. 3K), (9) small, polygonal (10) 1–2-celled South Australia (eight species, all endemics). The gemmae with normally strongly projected and other endemics are known from southern South thickened angles (Fig. 3B), (11) predominantly America (three species), Africa (Kenya, Rwanda, monoicous sexual condition (17 of the 24 known Tanzania) (one), Venezuela (one), Hawaii (one), species are monoicous), with (12) a frequent oc- Marion Is. (one). The most widespread species is currence of autoicous condition, and (13) devel- D. nanum known from Papua New Guinea, Suma- opment of androecia in some taxa on specialized tra, Java, Borneo, Ceylon, and Bhutan. small-leafed branches restricted in growth. My search for the ancestral group for Diplo- Such an ensemble of characters, never recall- phyllum showed that Diplophyllum shares many ing those of Scapania or Macrodiplophyllum, per- characters with some Australasian species of suade me to consider Diplophyllum as a group of Anastrophyllum, particularly A. novazelandiae a different origin. R.M. Schust. (Schuster 1966: fig. 4) and A. papil- A different origin of Diplophyllum presumes losum J.J. Engel & Braggins (Engel & Braggins designation of some basal group for evolution of 1998: fig. 3). These include inter alia leaf inser- the genus. Taking into account that the dioicous tion, shape and areolation; pattern of modifica- condition is characteristic of less advanced taxa, I tion of marginal cell walls resulting in a ± crenulate consider that at the base of Diplophyllum evolu- leaf margin; perianth and its mouth characteris- tion should be species with a dioicous or at most tics; gemma shape; oil-body characteristics. This an unstable distribution of sex organs. The pecu- suggests a Gongwanalandic, possibly Australa- liarities of leaf dentition should be considered as sian origin of Diplophyllum from Anastrophyllum. derived. These two assumptions lead me to the only known dioicous species with entire to hardly crenulate leaves, Diplophyllum nanum Herzog Douinia (Fig. 3D–K). In addition to the characters men- tioned above, this species is unique in having The genus Douinia was established by Buch rather large leaf cells and rounded gemmae with (1928). Among the generic criteria the following low projections of the cell angles. Moreover, its are noteworthy: non-keeled, loosely folded entire perianth is slightly plicate and contracted to the leaves with usually non-sheathing bases and nar- mouth. Rhizoids, in material seen from Sumatra rowly lanceolate lobes; peculiarly copiously cili- ± (Wijk 1716, L, LE), despite their rather scattered ate perianth mouth having branched cilia with distribution, often originate from stem cells adja- curved ends; 1-spiral elaters; and absence of gem- cent to the lowermost cells of the ventral lobe mar- ma production. Schuster (1979: 74, 1984: 67) sug- gin and may appear to be developed from it gested the new subfamily of Scapaniaceae, Doui- (Fig. 3D). All these features of D. nanum witness nioideae, broadly accepted by other hepaticolo- an absence of a stabilized diplophylloid morphol- gists (Grolle 1983, Smith 1990, and others). ogy and confirm its rather close position to the Douinia resembles Diplophyllum in general base of evolution of the genus. appearance, frequently incurved leaves and shape The other species, probably close to the base of perianth. Occasionally, the may develop of the genus, is the only known dioicous repre- ± lingulate diplophylloid ventral lobes (Fig. 4A sentative of the subgenus Austrodiplophyllum and C). It is also characteristic for Douinia to form R.M. Schust. of Diplophyllum, D. recurvifolium a ± thick-walled and often bleached marginal bor- C. Massal. It requires further investigation. der with ± distinct regular projections of walls of Present data on distribution of Diplophyllum, neighbor cells. The projections are stronger de- ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 277

Fig. 3. Diplophyllum taxifolium (Wahlenb.) Dumort. (A–C) and Diplophyllum nanum Herzog (D–K). — A, G: Ventral lobes of leaves, apical sectors. — B, H: Gemmae. — C, I: Basal sectors of ventral lobe margins. — D: Leaf with rhizoids near ventral lobe base. — E: Sector of shoot with perianth, antical aspect. — F: Sector of perianth mouth. — J: Leaf. — K: Distal part of ventral lobe with elongated lower median cells with shown papillae. — A–C drawn from 8.VIII.1997 Ignatov (LE); D–K from Wijk 1716 (L, LE). — Scale bars: a = 400 µm (D, E, J); b = 50 µm (A, C, F, G, K, I); c = 20 µm (B, H). fined to the leaf base (Fig. 4J, K and N). number of features which make its position within On the other hand, Douinia demonstrates a Scapaniaceae obscure. The characters of primary 278 Potemkin • ANN. BOT. FENNICI 36 (1999)

Fig. 4. Douinia ovata (Dicks.) H. Buch — A–C: Subfloral leaves. — D: Sector of shoot with perianth, antical aspect. — E: Leaf, mod. mesoderma-viridis. — F: Dorsal lobe apex of leaf from E. — G: Ventral lobe apex of leaf from E. — H: Ventral lobe margin of leaf from E, basal sector. — I: Sector of presumably gemmiparous shoot without gemmae, antical aspect. — J: Ventral lobe apex of male bract from L. — K: Ventral lobe margin of male bract from L, basal sector. — L: Male bract with marked bleached marginal sector, mod. pachyderma-fusca. — M: Sector of perianth mouth. — N: Ventral lobe margin of leaf from O, basal sector. — O: Leaf, mod. mesoderma- fusca. — P: Ventral lobe apex of leaf from O. — All drawn from 21.VII.1885 Kies (LE). — Scale bars: a = 50 µm (M); b = 400 µm (A–E, I, L, O); c = 50 µm (F–H, J, K, N, P). ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 279 importance are densely spiny papillose spores, 1- lished the family Delavayellaceae on the basis of spiral elaters, absence of gemmae, and long-cili- (1) the ability of the leaves to develop a postical, ate perianth mouth developing on plants with ± saccate, gibbous lobule which is so situated as to entire leaves. be somewhat appressed to the stem when the In the process of evaluating the above criteria is dry, (2) the dorsal lobe tends to be larger than from the position of the evolutionary ecology and the ventral, although the lobes are often subequal, morphology, their origin from a diplophylloid pro- (3) the distal part of the leaf is explanate and flat- genitor becomes clear. Distinctions of Douinia tened, and the lobes are non-conduplicate, and (4) from Diplophyllum are apparently related to evo- the gemmae are globose and unicellular and ap- lution of the former to exploit “non-diplophylloid” pear to be fundamentally different from the fasci- habitats. Douinia probably evolved as an epiphytic culate, catenulate-produced gemmae of the Scapa- hepatic of oceanic humid areas (the presence of niaceae. Douinia on other substrates — rocks, rotten wood My study of Delavayella revealed the follow- — may be secondary). In humid epiphytic condi- ing reasons to distinguish it as a separate family tions many water-preserving diplophylloid adap- (Fig. 5): (1) leaves absolutely non-keeled and (2) tations became “unnecessary” and were subjected succubous, obliquely inserted, (3) strongly broad- to gradual modification resulting in larger and ened basally, (4) divided by a very shallow sinus thin-walled cells, slightly defined marginal bor- (ca. 0.15–0.25 the leaf length) into two very nar- der, non-sheathing leaf bases, and hardly devel- row lobes, (5) of which the dorsal is always defi- oped marginal serration. It is remarkable that nitely larger than ventral, (6) female bracts simi- diplophylloid features of Douinia developed dis- lar to sterile leaves, differing in the deeper sinuses tinctly in plants of mod. densifolia-colorata (xeric and absence of sacs and showing no parallels with forms) and mostly not developed in plants of mod. the bracts of the other genera of Scapaniaceae, laxifolia-viridis (forms of wet habitats). Growth (7) perianth narrow, long exerted and compressed in principally different niches led to a transfor- in distal half only, being subcylinderic proximally mation of reproductive strategies expressed in (such the compression is probably not highly spe- suppression of gemma formation (gemmae are cialized as well as the perianth mouth, which is uncommon in epiphytic hepatics), enlargement of similar to leaf lobes), (8) branching pattern (ter- spore papillosity, and formation of 1-spiral elaters minal, pseudodichotomous and lateral interca- (capsules with very rare 2-spiral elaters occur spo- lary), (9) sporadic occurrence of rhizoids with radically as Schuster’s (1988: fig. 14, 5) and my branched ends, (10) abrupt development of almost own observations show). It is noteworthy that naked or small-leafed flagella associated with development of a long ciliate perianth mouth as- asexual reproduction. sociated with slightly dentate to entire leaves is The pattern of asexual reproduction remains characteristic also for Macrodiplophyllum (cf. unclear to me. Despite a careful study of materi- Figs. 2H and 4M). It is pertinent to mention that als with flagellae, no gemmae were found. They small-leafed upper shoot sectors, resembling those are apparently weakly attached to gemmiparous of gemmiparous plants of Diplophyllum, were vestiges. According to the original description by found in Douinia during this study (Fig. 4I). Stephani (1894: 4) accomplished in Stephani Such an analysis reveals a possibility of eco- (1910: 119), the gemmae are hyaline, globose, 1- logically induced transformation of Diplophyllum celled, on small scales appressed to the flagella in Douinia and persuades me to consider Douinia (“propagula in squamilis minutis appressis, hya- as a close relative of Diplophyllum, not meriting lina, globosa, unicellularia”). a subfamiliar segregation.

Blepharidophyllum and Blepharidophyllaceae Delavayella Schuster (1983: 541), validating the family status Buch (1928: 9, 10) pointed out the unclear family of Blepharidophyllaceae (Blepharidophyllum, position of Delavayella. Schuster (1961) estab- Clandarium (Grolle) R.M. Schust., Krunodiplo- 280 Potemkin • ANN. BOT. FENNICI 36 (1999)

Fig. 5. Delavayella serrata Steph. — A, B, G, L: Leaves (A – of mod. laxifolia, with small sac and sector of stem). — C: Sector of shoot with perianth, antical aspect. — D: Same shoot sector, postical aspect. — E: Perianth. — F: Shoot sector, postical aspect. — H: Dorsal lobe of leaf from G. — I: Basal leaf cells medially (lower left with papillae). — J: End of normal rhizoid. — K: End of branched rhizoid. — M, N: Female bracts. — O: Shoot sector with gemmiparous flagellum, ventro-lateral aspect. — P: Lateral sector of stem cross section of mod. laxifolia. — Q: Ventro-lateral sector of stem cross section of mod. densifolia. — R: Sector of longitudinal section of stem. — A, B, F–L, and O–R drawn from Tagawa & Kitagawa T3109 (NICH); C–E, M, N from 19.XII.1965 Tagawa & Kitagawa (NICH). — Scale bars: a = 500 µm (B–F, L–O); b = 50 µm (H–K, P–R); c = 400 µm (A, G). ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 281 phyllum Grolle), stated they have “a different phyl- pania are comparable with those of the subgenera ogenetic” history, and are “at best remotely allied of Scapania, not forming a generic hiatus and may to the basically Laurasian family Scapaniaceae”. be considered as gradually ecologically induced Engel and Smith Merrill (1998) showed the posi- and genetically stabilized modifications of the tion of the single Krunodiplophyllum species character expressions. within Diplophyllum subg. Austrodiplophyllum Macrodiplophyllum is recognized as a subge- R.M. Schust., and retained Clandarium as a sub- nus of Scapania: genus of Blepharidophyllum. They (Engel & Scapania subgen. Macrodiplophyllum (H. Buch) Po- Smith Merrill 1998) noted that the species of the temkin, comb. nov. — Basionym: Diplophyllum subgen. subgenus Austrodiplophyllum of Diplophyllum Macrodiplophyllum H. Buch, Soc. Sci. Fenn. Comm. Biol. show evidence of relationship to both Blephari- 3(1): 29. 1928. dophyllum and Diplophyllum. Species: Scapania imbricata M. Howe; S. microdonta (Mitt.) Müll. Frib.; S. plicata (Lindb.) Potemkin, comb. nov. I consider that leaf areolation of the species in — Basionym: Diplophyllum plicatum Lindb., Acta Soc. Sci. subgenus Austrodiplophyllum indicates a close Fenn. 10: 235. 1872. relationship with the subgenus Diplophyllum. The 4-ranked appearance, almost equally bilobed Diplophyllum is recognized as separate from leaves, and strongly squarrose-recurved leaf lobes Scapania and Scapaniaceae and placed in a sepa- of the Austrodiplophyllum species may represent rate family. ecologically induced parallelism with Blepharido- phyllum. Occurrence of rhizoids in fascicles in Diplophyllaceae Potemkin, fam. nov. Diplophyllum (Austrodiplophyllum) gemmiparum J.J. Engel & G.L. Sm., which is also characteristic Familiae Scapaniaceae similis, sed origine differt, for species of Blepharidophyllum, does not corre- quae ex characteribus sequentibus recognoscitur: late with the other characters and appears to show (1) dispositio primigenis basalis dentium margina- no close relationships of both groups. Bifid dorsal lium foliorum, (2) dentes projecturis parietum cel- lobes, sporadically occurring in Diplophyllum lularum contiguarum formantur, (3) plantae gene- incrassatum J.J.Engel & G.L. Sm. (Engel & Smith raliter minores, ut plurimum monoeciae, saepe Merrill 1998: 267, fig. 6: 8), are very different from autoeciae, (4) cellulae foliorum minores, (5) mar- the bisbifid leaves of Blepharidophyllum. gines foliorum limbo e cellulis parietibus crassis, The facts above confirm Schuster’s (1979, (6) gemmae polygonales e 1–2 cellulis, (7) perian- 1983:541) segregation of Blepharidophyllaceae thium distaliter pluriplicatum, saepe plus minus- from the other representatives of Scapaniaceae que ad orem constrictum. s. lato. It seems natural primarily because of the bisbifid leaves, which are uncharacteristic of Di- Type: Diplophyllum (Dumort.) Dumort. plophyllum but are observed in some other Gond- Similar to Scapaniaceae, but differing in the wanalandic groups (e.g., superficially similar to following complex of characters: (1) ± bordered Balantiopsaceae H. Buch), and also because of small-celled leaves with (2) primarily basal tooth the leaf areolation, which is principally different distribution and (3) tooth formation due to regu- from Diplophyllum. Absence of any intermediate lar projecting of walls of neighbor marginal cells, taxa between Blepharidophyllum and Diplophyl- (4) ± sheathing and rounded leaf bases, (5) ± fal- lum supports this idea. cate ventral lobes, (6) small 1–2-celled polygonal gemmae with ± projected thick-walled angles, (7) predominantly monoicous sex distribution, (8) CONCLUSIONS with frequent formation of androecia on separate intercalary ± specialized branches, and (9) devel- Macrodiplophyllum and Diplophyllum represent opment of pluriplicate, mostly ± contracted to the different groups from morphological and phylo- mouth lophozioid perianth. genetic points of view. Douinia is distinguished as a genus of Diplo- Distinctions of Macrodiplophyllum from Sca- phyllaceae derived from Diplophyllum and not 282 Potemkin • ANN. BOT. FENNICI 36 (1999)

Fig. 6. Hypothesized phy- logenetic relationships of Scapania. deserving the subfamiliar rank. REFERENCES Delavayellaceae and Blepharidophyllaceae are independent families separate from Scapaniaceae. Amakawa, T. & Hattori, S. 1955: A revision of the Japa- The Scapaniaceae contains only the genus Sca- nese species of Scapaniaceae. III. — J. Hattori Bot. pania Lab. 14: 71–90. . The hypothesized phylogenetic relation- Buch, H. 1928. Die Scapanien Nordeuropas und Sibiriens ships of Scapania are shown in Fig. 6. 2. Systematischer Teil. — Soc. Sci. Fennica, Comm. The family Scapaniaceae is an example of how Biol. 3(1): 1–177. progressive and repeated study gradually narrowed Engel, J. J. & Braggins, J. E. 1998: Austral Hepaticae. 27. our concept of it to the point where a more ho- The genus Anastrophyllum (Spruce) Steph. (Jungerman- mogenous taxon resulted (Schuster 1961: 202). niales) in Australasia, with a synopsis of austral taxa. — J. Bryol. 20: 371–388. Engel, J. J. & Smith Merrill, G. L. 1998: Austral Hepaticae Acknowledgements: This paper is based mainly on my study XXV. Krunodiplophyllum Grolle and a revision of the of Scapania and numerous floristic studies carried out dur- Australasian species of Diplophyllum (Dum.) Dum. ing this decade. Therefore I thank all my colleagues and (Scapaniaceae, ). — J. Hattori Bot. friends who have helped and supported those studies in dif- Lab. 84: 241–283. ferent ways. Help of Dr. Alexei Oskolski with Latin trans- Grolle, R. 1983: Nomina generica Hepaticarum; references, lation is highly appreciated. I also express my deep grati- types and synonimies. — Acta Bot. Fennica 121: 1–62. tude to the Curators and staff of H, G, JE, NICH, NY, WTU, Kitagawa, N. 1965: A revision of the family Lophoziaceae UBC for arranging loans and/or for space and help during of Japan and its adjacent regions. I. — J. Hattori Bot. visits. The work was supported in part by grants #98-04- Lab. 28: 239–291. 49828 and #98-04-49827 of the Russian Fund of Basic Re- Konstantinova, N. A. & Potemkin, A. D. 1994: Studies on searches. Scapania sphaerifera (Hepaticae). — Ann. Bot. Fennici ANN. BOT. FENNICI 36 (1999) • Circumscription of the family Scapaniaceae 283

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