植物研究雑誌 J. J. Jpn. Bo t. 66: 66: 134-146 (1 991) Studies in the Systematics of Filmy Ferns VIII C 同phalomanes Presl subgen. Cephalomanes Kunio IWATSUKI Botanical Botanical Gardens ，Faculty of Science ，University of Tokyo ， 3-7-1 ，Hakusan ，Bunkyo ・ku ，Tokyo ， 112 JAPAN コケシノブ類の分類に関する研究班 ソテツホラゴケ亜属 岩槻邦男 東京大学理学部附属植物園 112 東京都文京区白山3-7-1 (Received (Received on January 7， 1991) A filmy fern subgenus ， Cephalomanes subgen. Cephalomanes ， was taxonomically revised. Taxo- nornic nornic characters were surveyed and re-evaluated from systematic viewpoints. Six species including infraspecific infraspecific taxa were recognized and keyed ou t. Enurneration of all taxa was given with notes on distribution distribution and taxonomy. C句phaloman 回 crassum and C. madagascariense are restricted to particular localities localities and are rare with a few collections. C 句phalomanes densinervium and C. singaporianum are also also restricted to narrow areas and are not variable ， but C. atrovirens and C. javanicum have wide areas areas of distribution and are variable with many infraspecific taxa. Rheophytic nature ， or adaptation to to the habitat along stream ， is discussed in relation to habitat and phenetic features. (Continued (Continued from Acta Phytotax. Geobot. 35: 165-179 ， 1984.) Cephalomanes was described by Presl in 1843 following to Copeland in its position. Most of the on the basis of C. α trovirens and some ten species species have been ill-defined ，and a revision is have currently been referred to subgen. necessary for this complex group. Cephalomanes (Iwatsuki 1984) from the Old In the present part of this series ， subgen. World tropics: East Madagascar ， India to con- Cephalomanes will be treated in its strict sense ， tinental tinental Southeast Asia ，Hainan ，Taiwan ， southern though the generic classification was revised and Ryukyus ，throughout 恥1alesia to Polynesia ， south broadly circumscribed leaving Cephalomanes s. str. to to Queensl 加 d. Copeland (1 938) sugg 回 ted th 瓜 this as a subgenus (l watsuki 1984). Before going further was derived from the Vandenboschia radicans on each species ，it may be contributive to note a group and placed it next to M 白 opteris and few distinct features of subgen. Cephalomanes in Callistopteris. 恥10rton (1 968) ranked it in a section general to elucidate the systematic evaluation of of Trichomanes subgen. Pachychaetum 如 d placed their characteristics. it it together with sects. Nosopteris and Callistopteris ， 句、A 『 d June June 1991 Journal of Japanese Botany Vo l. 66 No. 3 135 The specimens of most larger herbaria were The pinnae are principally subentire to denticu- examined examined on the way of this study. Sincere thanks late ， and the dentation at margin is uninervate at are are due to the directors and curators of these least at its end. Th e uninervate dentation is in most herbaria ，some of which are recorded in the tex t. cas 岱 very short and hardly waved at margin; in The author is grateful to Dr. 恥1asahiro Kato who some cases ，however ， the dentation elongates ， or read read the manuscript and gave it valuable is separated from at the base or near costae ， comments. comments. A p 紅 t of this study was supported by forming very narrow or linear segments like those a Grant-in-Aid for Scientific Research no. of Macroglena in appearance. Lamina is nearly 02454017 from Ministry of Education ，Science and lacking on the basiscopic side ， where several hair- Culture. Culture. like segments ， or linear uninervate dentations ， occur. occur. The origin of this type of variation is Taxonomic characters unknown ， but there 紅 e various intermediate forms Frond construction which suggest that this type of variation is under The fronds 紅 e simply pinnate throughout ， the in f1 uence of environmental conditions. The except except for C. crl α ssum in which free pinnae 訂 eonly hair-like segments are present throughout subgen. a few at the base of a frond and more than 20 Cephalomanes ，and there is no specific difference lateral lateral pinnae are adnate to the rachis ，giving an of this type of variation observed. The linear appearance appearance of pinnatifid construction. The adnate segments may suggest the relationship of this group b 出 e of pinnae is contiguous to that of neighboring to Macroglena ，and the other features ，including ones ，and the rachis is broadly winged throughou t. soral morphology and cell-walls ， are not incon- In In the other species ， the rachis is usually described sistent with the suggested relationship. as as terete ， but in fact it is very narrowly winged at The species of Cψ halomanes usually become least least in its upper half. The wing is more distinct soriferous at a very young stage ，and even a small in in smaller plants ，and young leaves usually have frond bears sori rather commonly. In the small distinct distinct wings on both sides of a rachis. plants in which there are little development of Lamina segments dentation at margin of lobules ， the sori appear In In sterile segments ， the margin is usually sub- comparatively large and the sinus is distinc t. entire entire to denticulate or variously lobulate. In fertile Venation segments ，sinus 紅 e often formed and sori are The venation pattern is rather difficult to trace placed placed at their bottom. The linear segments (see in pinnate fronds because of various modifications. the the next paragraph) 紅 e often separated from the In all the species of Cψ halomanes ， venation is laminae laminae next to the sinus. Even in the sterile anadromous and ， as the species with this venation segments ， the sinus is sometimes formed 泊 a place in general ， the sori are paratactic in 紅 rangement equivalent equivalent to the sinus of fertile segments. (cf. Prantl 1875 ，Morton 1968). In dwarfed However ， in portions without any sori ， as seen in species ，it is rather difficult to distinguish the vena- the .the distal portion of C. singapori α， num ， there is no tion type ， but the general tendency Can be traced laceration laceration of pinnae or at most minute denticula- especially when the soral position is also taken into tion. tion. The denticulation is distinct in this section account. 創 nong the filmy ferns generally with univeined By simply pinnate construction of fronds with teeth. teeth. lanceolate outline ，Ceph α lomanes subgen. 136 136 植物研究雑誌第66 巻第3 号 平成3 年 6 月 Cephalomanesis Cephalomanesis comparable with the New World tics. Copeland (1933 ， p l. 53) illustrated the group group of filmy ferns referred to Trichomanes different distribution of sori on one pinna for five subgen. subgen. Trichomanes. However ， the latter is species. If we tre 剖 only typical extremes we can distinct distinct in having catadromous venation and distinguish different forms: 1) When sori 紅 eafew epitactic 紅 rangement of sor i. In some Am erican on a pinna ， they are at the distal end or on the species species with dimidiate basiscopic base of pinnae ， acroscopic side near distal end; on a pinna with the the venation is rather irregular and needs further several sori ， they are on the acroscopic side from observation observation especially on young plants. The distal end towards acroscopic base; and in case in difference difference in frond construction seems to indicate which there are more numbers of sori ，th 句T are also a systematic remoteness between Trichomanes on the basiscopic side. 2) Wh en sori 紅 ea few on subgen. subgen. Trichomanes and Ceph α lomanes subgen. a pinna ， they are on the acroscopic side usually at Cephalomanes ，and the former may better be midst between distal and basal ends; and even in separated separated from the latter and its allies at generic case there are more sori on a pinna ， they are rank rank (Iwatsuki 1984). restricted to the acroscopic side ， though the sori Distribution Distribution of sori are observed even at the distal end. This typical The sori are distributed on a frond from the difference is observed in most distribution 紅 eas ， apical apical portion downwards ，except for a case in C. but my field observation does not admit this foersteri ，a problematic form which was described difference as to hold a specific difference. The ぉ having sori only on the middle and lower pinnae. distribution of the sori on a frond is rather Sori Sori are sometimes borne only at the very apical variable ， and it is hardly concluded from the varia- portion portion of fronds forming spike-like structure ， tion of phenetic characters that the above tendency apparently apparently relating to plant size. There are several is genetically fixed. The two varieties 紅 e geo ・ species' ‘species' distinguished only by this particular graphically isolated in general but coexist in character ， in addition to the others ， such as T. Borneo ， where this feature is more variable. acrosorum ， T. boryanum var acranthum ， T. kingii ， In C. singaporianum the distribution of sori on and T. sumatranum. a pinna is different from that of the other species. Plants Plants with the sori gathering to the apical part The sori have a tendency toward being distributed of of fronds in most cas 白 have larger involucres and at the basal portion of a pinna: most sori are on long long stalks. It is unknown whether they are under the basal half of acroscopic side of pinnae ，and an an influence of the position of sori or not ， though even in fully fertile plants with sori on both the the general tendency is obvious in the species of acroscopic and basiscopic sides ， most sori distri- subgen. subgen. Cephalomanes. The combination of these buted in basal and middle portions of pinnae ， never characters ，larger sori with long stalks gathering on the distal end. This is 仕ue also in the case of at at apical portion of fronds ， forms a spike-like C.