On the Structure of Hawaiian Tree Ferns, with Notes on the Affinity of the Genus Cibotium*

By

Yudzuru Ogura

With 6 Text Figures

When the writer had studied the anatomy of Cibotium Barometz SM. from southern parts of Japan (1927), he desired in vain to study , other species of this genus. Fortunately he had, in the spring of 1930,. an opportunity to visit the Hawaiian Islands and to study the ana- tomical structure of tree ferns, or the Cibolium species, growing there

HISTORY AND MATERIAL . The genus Cibotiztm includes a few species growing in tropical regions; three species in the Hawaiian Islands, five in America , and four (sometimes to be included in one species) in Asia . They are mostly tree ferns having tall erect stems, while Asiatic species are small having creeping rhizomes. The anatomical study of Cibotium Barometz has been undertaken. by several authors:-PARMENTIER 1899, GWYNNE-VAUGHAN 1903 , BOWER 1926, OGURA 1927, HAvAT.A. 1929. According to their observa- tions it has a creeping rhizome clothed with long hairs, and in the rhizome is a solenostele or dictyostele without surrounded by the sclerenchymatous sheath, which is one of the characteristics of the Cyatheacean stem. It has no medullary bundle which is also absent throughout the species of Dicksonieae, one of the tribes of the Cyatheaceae. Its petiole contains numerous bundles arranged in a complex manner, characteristic in all species of the Cyatheaceae . On the structure of the stem of other species of this genus there is no detailed study, and it was very desirable to the writer to compare

* Contributions to Morphology and Genetic s from the Departments of Plant- Morphology and of Genetics, Botanical Institute, Faculty of Science, Tokyo Imperial University, No.95. [Vol.XLIV, No.525 468 THE BOTANICAL MAGAZINE them with C. Barometz. The petiole of Cibotium, however, has been observed to a certain extent, concerning the arrangement of vascular strands, by THomAE 1886, IIACHMANN1889, PARMENTIER 1899, BERTRAND& CORNAILLE1902, PELOURDE1909. According to them the bundles are arranged in the characteristic manner just as in C. Barometz and Dicksonia. In the Hawaiian Islands are three species known as Cibotium:- C. Chamissoi KAULFUSS, C. Menziesii HOOKER, and C. glaucum HOOKER& ARNOTT. They grow in the rainy parts of all islands, in some cases in dense forests. The writer collected three species of Cibotium at Glenwood on the Island of Hawaii, near the road running from Hilo to the Kilauea Volcano, where a fairly large forest of tree ferns was seen. C. ChaMissoi and C. Menziesii, both very common on the islands, are distinguished easily from each other in the field; the former has a comparatively shorter but thicker trunk than the latter; moreover, hairs are equally golden-yellow in the former, while blackish or brownish on the crown and petiole in the latter. C. glaucum which occurs rarely was not collected in this district, while another species collected seems not to be described in the botanical list. This is recognizable in the field by its slender trunk, small fronds and also by the pale yellow colour of the trunk tissue when cut down. This seems to be a new species, and will be described with Prof. T. NAKAI as Cibotium hawaiense. Cibotiurn(Eucibotium) hawaiense NAKAI & OGURA,sp. nov. Caudexerectus 3-5 metralisaltus potiusgracilis 6-9 cm. diametienscum gemmis adventitiiscrebre ramulosus, juventute pilis cupreo-aureislongissimis saepe 5-6cm. longisdensissime obtectus, inferior rklicibusatro-fuscis fere toto obtectus. Medulla aurescens.Frondes in apicecaudicis congestae alternae 1-2 metralislongae bipinnatae ambitu ovato-oblongae;stipites cum caudiceinarticulati persistentes virides 15-30cm. longi basi 20-25mm.diametientes ubi extus cum pilis aureo-griseiselongatis dense vestiti; rachisfrondis glabra viridis; pinna pinnata infima ambitulanceolata 50-60 cm. longa20-25 cm. lata utroquelatere 25-30 pinnulata, rachi primopilis multicellulatis (cellulisterminalibus elongatis fuscescentibus ceteris brevibus albidis), pilosa demum glabrescente;pinnula subpectinato-pinatifidafere sessilislineari-lanceolata attenuata quam 12mm. brevior 1-2mm. lata chartaceasupra lucida infra glaucescenscum rachibussubfurfuraceo-pilosa, nervis simplicibusvel rarius bifurcatissupra impressis infra elevatis,lobis oblongis utrinque subrevolutis fertilibus praeter apicemutrinque soriferis.Sori marginales secus inargines loborum pinnarum biseriales utrinque 2-5 (1-6). Indusiumfuscescens primo saccatuin maturitate in valvisbirds fere aegualitus (interiore parce minore) apertum 1mm. longum 1-1.5mm. latum subquadrangularibus. Sporangiumlonge stipitatumannulo obliquo incompleto 24-36 cellulato fusco, cellulis stomii 13-15. Paraphyseselongati subfiliformesunicellulati fusci. Sporae tetra- hedralesfuscescentes. Hab. Sept., 1930] OGURA-STRUCTURE OF HAWAIIAN TREE FERNS 469

Hawaii: Hilo insulae Hawaii (Y. OGURA, typus in Herb. limp. Univ. Tokyo). This endemic Cibotium was first recorded by RIPPERTON(1924), a chemist, who investigated the starches of tree ferns in the Hawaiian Islands. He gave the follow- ing sentence (p.3) with a photograph (pl.1, fig.3); " Another species, commonly known as the "Men," is easily recognised in the Hilo district by its very slender trunk, smaller fronds, dull, lusterless, rather scant, yellowish-brown pulu, and nearly naked stipes." In the list of ferns of the Hawaiian Islands published recently by C. CHRISTENSEN (1925), only three well-known species (C. Afenziesii, C. Chamissoi, C. glaucum) were enumerated. The following description is based on' three species mentioned above:-C. Chamissoi, C. Menziesii, and C. hawaiense.

STRUCTURE OF THE STEM

The stem is erect, usually 3-5m. in height, sometimes reaching more than 10m. in C. Menziesii, and is crowned by some large leaves. The latter remain only at the top of the stem, old ones falling off; they do not fall from their very bases, so that the characteristic scars as seen in some Cyatheacean species are not to be seen on the stern surface, The leaves are arranged on the stem regularly in the intermediate type of 2/5 and 3/8 divergence (cf. RIPPERTON1925,p.6, fig.1). Adven-

Fig.1. Cibotium Chamissoi; photograph of a cross section of the stem. Tufty mass outside consists of hairs; root mass has been removed (x 1/2) 470 THE BOTANICAL MAGAZINE [Vol.XLIV, No.525 titious roots are abundantly produced all round the stem covering its surface, and those from the upper parts cover the root mass of the lower parts, thus forming a very thick root cover, which serves to support the large trunk. This tendency is most prominent in C. Chamissoi in which the root mass reaches more than 1m. in diameter, while the stem proper within this mass measures 10cm. in diameter; these features are similar to those of the typical Cyatheaceae. The thickness of the stem is, of course, different in individual plants; in general, C. Ckamissoi is thickest measuring 10-13 cm. in diameter, while C. Menziesii measures 6-11cm., and C. kawaiense 6-9cm. The stems of the three species agree in their essential internal structure. The cross section of the stem is properly circular, but as the parts of attachment of leaf bases bulge out, its outline is rather lobed (Figs. 1-2). In one cross section three to five of such bulged parts are found, each including vascular bundles with various forms of peculiar arrangement, which are going as leaf traces to the petiole. Within the stem is a stelar ring with lobes running nearly parallel to the outline of stein. Its diameter measures about 5cm. in the stem with a diameter of 6cm. The stele is dictyostelic, several leaf gaps overlapping in one cross section. In C. Barometz it is sometimes dictyostelic, sometimes solenostelic. This is, however, not an important difference, fcr, in this case the dictyostely and solenostely are caused merely by the longness or shortness of the internodes. On the periphery of the stem is a thick brown sheath, which is the important protecting tissue, and within the stem such a mechanical tissue no longer exists. The mode of departure of the leaf traces from the stem stele was investigated by means of successive cross sections. It agrees completely with that of C. Barometz. As several leaf gaps overlap, some stages of leaf trace formation may be seen even in one cross section (Figs.1-2). The epidermis and some cell layers underneath are parenchyma- tous, and gradually pass to the thick sheath, whose membrane is very thick, brown in colour. The thickness of this sheath measures 1-2mm., sometimes 3mm. in large stems, and it is very prominent in C. hawaiense reaching more than 4mm. in thickness (Fig.5). Hairs on the stem surface are very long reaching 2-5cm., they are also persistent densely covering the stem surface (Fig.1). They consist always of one cell row. Their wall is thin, yellowish in colour, and as their contents are lost they usually curl up to a certain extent. The stelar ring is 1-1.5mm. in thickness, and consists of an amphiphloic vascular bundle with distinct endodermal layer. The spt., 193o] OGURA—STRUCTURE OF HAWAIIAN TREE FERNS 471 greater part of the stem is occupied by whitishfundamental tissue whose cells contain a great amount of starch grains, which are used by the natives as a source of food.

Pig.2. Cibolium Menziesii; cross section of the stem; hairs and root mass have been removed. A, B, position of leaves; sh, sheath; rt, root trace; st. stele; lg, leaf gap; lt, leaf trace: n. netiole base (x 3/4)

STRUCTURE OF THE LEAF

The leaf is very large, largest in C. Menziesii measuring 2-3'm. or more in length, while in C. Chamissoi 1.5-2m., and in C. hawaiense 1-1.5m. The petiole is fairly long and thick, its basal part covered with long yellowish hairs reaching more than 10cm. in length. They, are always uniseriate like those of the stem. In C. Menziesii, hairsat the distal part of the petiole become hard and brownish or blackish, 472 T HR BOTANICAL MAGAZINE Vo1. XLIV, No.525 and at more distal part, where the pinnae are borne, they are short, blackish and very hard like small spines, but they consist always of one cell row. The rachis is generally naked. The petiole at its basal part is elliptical in cross section, the upper side being somewhat flat, usually with slight lateral depressions. In general, it is thickest in C. Chamissoi reaching 4-5cm. in lateral diameter, while in C. Afenziesii 3-4cm., and in C. hawaiense 2-3cm. Within the petiole are vascular strands peculiarly arranged most of them are arranged on the periphery, some others occupy the central part forming two bands on the median upper side and on both lateral sides (Fig.3). Their number varies according to the size of the petiole; in one of the largest petioles of C. Chamissoi it reaches 90-100. Though the bundles are separate from each other at the basal part (Fig.3A), they are gradually connected upwards within the petiole (Fig.3B), and at its upper part they connect into three wavy bands, upper two in 7-form, and the lower one in an arc with incurved margins (Fig.3C). Further in the rachis three bands connect and form a continuous band. This mode of arrange- ment of vascular bundles agrees with that of C. Barometz and also with some other species of Cibotium observed by some auth ors At the basal part of a large petiole, though not always, the bundles at the upper side arrange themselves in an arc, and two rows of internal bundles at that Fig.3. Cibotium Menziesii; part in the form of an inverted U (Fig.3 cross sections of the petiole, A). At the part where the bundle con- through the basal (A), middle nection takes place, the upper arc and the (B), and upper parts (C), show- U-formed internal arc connect respectively ing the arrangement of vascular forming corresponding wavy bands (Fig.3 strands. (x 3/4) B); and then at the median line two bands are interrupted a little and the ends of different arcs are connected to form two bands in C7-form (Fig.3C). Such a mode of bundle connection was not observed in C. .Baromaz, but has been figured by BERTRAND& CORNAILLE(1902) in C. regale. The smaller: petiole in the present species has the type of C. Barometz, and the type above given may be an advanced one. BERTRAND& CORNAILLEhave observed in C. regale, that at the upper sept., 1930] OGURA-STRUCTURE OF HAWAIIAN TREE FERNS 473 part of the petiole, its vascular bundles are connected into a continuous ring form. The mode of departure of pinna trace from the rachis bundle is the same with that of C. Barometz. The structure of the vascular bundle and fundamental tissue is also the same with that of C. Barometz. Sporangia are found within the involucre consisting of two shell- like valves at the margin of pinnules. The annulus is incomplete, and the stalk is attached obliquely. The development of sporangia was studied by BOWER (1908) in C. Scheidei.

BRANCHING OF THE STEM

Lateral buds are very commonly found in the field on the surface of the stem, especially abundant in C. Chamissoi and C. hawaiense (Fig.4) in the former the bud is massive, while in the latter it is slender corresponding to the stature of adults. When small, they are covered under the root mass, but usually they grow as large as a few cm. bearing several foliage leaves at the top. In the native forest some are found growing in various stages of development, and it is not un- common to find one or two buds grow as large as the parent, giving a branched tree aspect; this may be caused by the injury of the parent. Such buds have been observed in C. Barometz very commonly, in which, however, the writer has never seen the case when the bud actually grows up, though he sug- gested its possibility (1927, p.273). The mode of formation is the same with C. Barometz. Their formation is always associ- ated with the bulging out of the leaf trace. As in the case of C. Barometz Fig.4. Cibotium hawaiense; photograph of a part of the stem, showing three lateral the vascular bundles of the buds, sprung out of fibre-like root mass. (•~ 1/3) 474 THE BOTANICAL. MAGAZINE [ Vol.XLIV, No. 525

Fig.5. Cibotium hawctiense; cross section of the stem at the level where a bud is produced. b, bud; other ex- planations as in Fig.2 (x 3/4) bud are derived from the stem stele at the place where the latter bulges out to form the leaf trace bundle (Fig.5). In two cases the writer found that the leaf trace bundle became abortive after the vascular bundle branched to the bud. The fundamental tissue of the stem and the bud is completely connected. At the base of the bud, its bundle is protostelic, and becomes gradually solenostelic and then dictyostelic.

AFFINITY OF THE GENUS Cibotium Though the Hawaiian species of Cibotium differ in the erect habit of their stems from C. Bayometz, their anatomical features agree with the latter. On the creeping habit of the stem of the Cyatheaceae the writer has discussed in Alsophila acaulis and A. formosana (1927, p.308), which had the same anatomical structure as other species of Alsophila with erect stems, so that C. Barometa and the present Hawaiian species are in the same relation as the creeping and erect Sept., 19301 OGURA—STRUCTURE OF HAWAIIAN TREE FERNS 475

species of Alsophila; that is to say, the difference of the stem habit gives no influence to the internal anatomical structure. Beside C. Barometz, C. assamicum, C. Czinzingii and C. sumatra- num, all from tropical Asia, have creeping rhizomes though their internal structure is uncertain, while the Hawaiian species as well as American have tall erect stems. From these differences of geographical distribution and stem habit, Prof. B. HAYATA (1929) recently proposed to separate the genus Cibotium into two: subgenera, Microciboliztnz including Asiatic species and Euciboii um including American and Hawaiian species. When the writer published the study of C. Barometz, the internal structure of other species of Cibotium was unknown, and he supposed that they might have a sclerenchymatous sheath around the stelar ring just as in other Cyatheacean species (1927, p.315). This stelar sheath is characteristic in the Cyatheaceae and is well developed even in the allied genus Dicksonia (REICHARDT 1859, SCHUTZE 1906, WILLIAMS 1925). Absence of such a sheath among the family was reported in Thyrsopteris elegans, Alsopkila blechnoides and Cibotium Barometz, of which the former two are somewhat different from the typical Cyatheaceae being grouped in special groups (cf. OGURA.1927, p.315), so that the absence of the sheath in Cibotium, probably in all species, should be carefully considered. It is of course very necessary to have such a stelar sheath as a support of the large stem of the tree fern. But, in the Cyatheaceae there are a few species which do not grow tall, but remain small (Alsophila blechnoides, A. formosana, A. acaulis); even such species provide the sheath around the stelar ring. Accordingly we might con- sider that the presence of the sheath has developed in the Cyatheaceae associated with the tree habit and then become fixed in this group in spite of the small or large habit. On the contrary, the absence of the sheath , in Cibotium might have been the proper character of this genus, and this tissue would not have developed even if the stem had grown in tree form. Tree-like species of Cibotium can grow as tall as other species of the Cyatheaceae, and this fact suggests that the tallness of the stem is not the only cause which has derived the sclerenchymatous sheath. There is another good example to , explain this relation. At the place where the above mentioned species of Cibotium were collected, the writer observed Sadleria cvatheoides KAuLFuss, a Polydodiacean tree fern, which grows together with Cibotium. This fern has a tree- Vol. XLIV, No.525 476 THE BOTANICAL MAGAZINE like stem as tall as 3-5m., the apex is crowned with large foliage leaves, and the stem surface is covered with root mass, so that the general habit and appearance are quite the same with Cibotium. The cross section of the stem (Fig.6) is properly circular, 10cm. in diameter, but the outline is fairly lobed owing to the attachment of petiolar bases arranged nearly in 3/8 divergence. The stele is dictyostelic, 3.5cm. in diameter each meristele is small and massive, leaving broad gaps between the neighbouring meristeles. In the broad cortex are found many leaf traces in various modes of development. The mechanical tissue is represented only by the peripheral brown sheath, and no other tissue for protection is found within the stem. This may be a very interesting example to show how the stelar sheath has not always developed associated with the tallness or bigness of the stem.

Fig.6. Sadleria cyatheoides; cross section of the stem. Explanations as in Fig.2. (•~ 3/4)

Now, Cibotium is usually included with Dicksonia and others in

Dicksonieae, one of the tribes of the Cyatheaceae (DIELS 1902, CHRIST Sept., 1930] OGURA—STRUCTURE OF HAWAIIAN TREE FERNS 477

1897, CHRISTENSEN 1906) or one of the subfamilies of the Dicksoniaceae (BOWER 1926). In most characteristics, vegetative as well as repro- ductive, Cibotium is very much like Dicksonia, and both genera have been naturally considered to be mostly related to each other, the former genus being sometimes included within the latter (HOOKER & BAKER 1883). But, if the stelar sheath is taken into consideration, its absence or presence in both genera should show another aspect of their re- lationship, so that the genus Cibotium without such a sheath ought to be separated from Dicksonieae or Dicksoniaceae, representing either a distinct family or at least a distinct tribe of the family. The writer intends at present to establish a tribe Cibotieae among the Cyatheaceae. This tribe includes one genus Cibotium, and stands closely with the tribe Dicksonieae.

SUMMARY 1. Three species of Cibotium from the Hawaiian Islands, C. Charnissoi, C. Menziesii, and C. hawaiense, of which the last is new, have been anatomically investigated. 2. The internal structure of the stem and leaf agrees with that of C. Barometz, a well-known species, though the latter differs externally from the present species in its creeping habit of the stem. 3. The stem includes the dictyostele not surrounded by the scleren- chymatous sheath, the characteristic mechanical tissue of the Cyathea- ceae. This tissue will be absent probably in all species of Cibotium. 4. On the stem surface are observed numerous lateral buds, whose stele and fundamental tissue connect directly to the corresponding tissues of the parent stem. They grow under necessary circumstances as tall as the parent. 5. Creeping and erect habit of the stem has no influence on the internal structure of the stem in Cibotium and Alsophila. 6. From the absence of a mechanical sheath around the stele, it would be undertaken to, separate Cibotium from the Dicksonia-group, and to establish among the Cyatheaceae a tribe Cibotieae including the genus Cibotium. July 1930 Botanical Institute, Faculty of Science, Imperial University of Tokyo

LITERATURE BURTRAND,C. E. & CORNAILLU,F. (1902) etude stir qulques caracteristiques de la 478 THE BOTANICAL MAGAZINE [Vol.XLIV, No.525

structure des Filicinees actuelles. I. Partie. Tray et Mein. Univ. Lille. Torn. 10. BOWER, F. O. (1908) Origin of a land flora. London. (1923-26) The ferns. Vols. I-II. - Cambridge. CHRIST, H. (1897) Die Fartikrduter der Erde. Jena. CHRISTENSEN, C. (1906) Index filicum. Hafniae. ,- (1925) Revised list of Hawaiian Pteridophyta. Bishop Museum Bull. 25. Honolulu. DIELs, L. (1902) Cyatheaceae. ENGLER & PRANTL's Naturl. Pflanzenfam. I. Teil. Abh. 4. Leipzig. GWYNNE-VAUGHAN, D. T. (1903) Observations on the anatomy of solenostelic ferns. Ann. of Bot. Vol.17. HAYATA, B. (1929) Microcibolium, a new subgenus founded through the considera- tion of the stele structure of Cibotium barometz. (japanese) Bot. Mag. Tokyo. Vol.43. HILLEBRAND, W. (1888) Flora of the Hawaiian Islands. London. HooKER, W. J. & BAKER, J. G. (1883) Synopsis filicum. II. ed. LACHMANN, J. P. (1889) Contributions a l'histoire naturelle de la racine des Fougeres. These, Paris. OGURA, Y. (1927) Comparative anatomy of Japanese Cyatheaceae. Jour. Fac. Sci. Imp. Univ. Tokyo. Bot. Vol.1. Pt. 2. PARMENTIER, P. (1899) Recherches sur la structure de la feuille des Fougeres et sur leur classification. Ann. Sci: nat. Bot. Ser. 8. Tom. 9. PELo-uRDE, F. (1909) Recherches comparatives sur la structure des Fougeres fossiles et vivantes. Ann. Sci. nat. Bot. Ser. 9. Tom. 10. REICHARDT, H. W. (1859) tTher die Gefassbiindel-Vertheilung in Stariime und Stipes der Fame. Denksch. Akad. Wiss. math. naturw. Cl. Bd. 17. RIPPERTON, J. C. (1924) The Hawaiian tree fern as a commercial source of starch. Hawaii Ag. Exp. Stat. Bull. 53. SciltTzU, W. (1906) Zur physiologischen Anatomie einiger tropischen Fame, besonders der Baumfarne. Beitr. wiss. Bot: Bd. 5. THOMAE, K. (1886) Die Blatt stiel der Fame. Bin Iktitrag zur vergleichende Anatomic. Jahrb. wiss. Bot. Bd. 17. WILLIAMS, S. (1925) Some points in the anatomy of Dicksonia. Proc. Roy. Soc. Edinburgh. Vol.45.

概 要

布 畦 産木 生羊 歯 ノ構 造 並 ビニたか わ らび屡, ノ類 縁 關係

小 倉 謙

辛 ハ北米合衆國ヨリ露國 ノ途上布睦群島二立寄 リテ、同島産 ノ木生羊歯ノ内部構 Sept., 1930] KUMAZAWA-AFFINITIES OF GLAUCIDIUM 479

造 ヲ 知 ル ノ機 ヲ得 タ リ 。 同 島 産 ノ木 生 羊 歯 ハ 主 ニ へ ご科 ノ た か わ らび 属 二属 ス ル モ

ノ ニ シ テ 、 ソ ノ三 種((Cibotium Chαminssoi,C.Menziesii,C.hawaiense)ニ ツ キ テ 観

察 セ リ。 コ レ ラ ハ ス ベ テ 茎 ノ高 サ 数 米 二達 ス ル 範 例 的 木 生 羊 歯 ニ シ テ 、 莖 ノ直 径 十

糎 ヲ超 ユ ル 事 尠 カ ラ ズ 。

莖 ノ 周 園 ニ ハ 厚 キ 厚 膜 組 織 鞘 ア リ 、内部 ニ ハ 中 心 柱 ヲ藏 ム(第 一 、二 、五 圖)。 中 心

柱 ハ 網 状 型 ニ シ テ 所 々外 方 二膨 出 シ テ 葉 跡 トナ リ 、 ソ ノ 周 ニ ハ へ こ 科 植 物 ニ特 有 ナ

ル 厚 膜 組 織 帯 ヲ 缺 ク 。 葉 柄 ニ ハ 維 管 束 條 多 数 ア リ、 へ こ科 植 物 ニ特 有 ナ ル 排 列 ヲ示

ス(第 三 圖)。

コ ノ莖 及 ビ葉 ノ構 造 ヲ本 邦 産 た か わ ら び(C.Barometz)(本 誌 四 十 雀 参 照)ニ 比 ス

ルニ、毫モソノ本質 二於テ解剖學上ノ相違ヲ認 メズ、只外観上 コノ種 ハ木状莖ヲ有

セズシテ些小ナル爬伏根莖ヲ有スルヲ著ルシキ相違 トス。彼此相比 スルニ、たかわ

ら び 屬 ノ莖 ハ 、ソ ノ直 立 トス ル ト爬 伏 ス ル トヲ 論 ゼ ズ.中 心 柱 ハ 厚 膜 組 織 帯 ヲ以 テ 包

擁 セ ラ レ ザ ル モ ノ ト云 フ ベ シ 。尚 布 哇 産 ノ う らぼ し科 ニ 属 ス ル ー 木 生 羊 歯(sadleria

)ノ 莖 ハ 、 ソ ノ高 サ数 米 、太 サ 八 糎 ニ及 ブ モ ノナ ル ガ,ソ ノ 中 心cyatheoides 柱 ニハ 厚

膜 組 織 ヲ 伴 バ ズ(第 六 圖)。 故 ニ 該 組 織 ノ發 達 ハ 必 ズ シ モ 莖 ノ直 立 性 或 ハ巨 大 性 ニ

直 接 關 係 ヲ 有 ス ル モ ノ ニ 非 ザ ル ベ ク.た か わ らび 屬 ニ該 組 織 ヲ鮫 ク ハ コ ノ屬 ノ本 來

ノ特 質 ナ ラ ン。

元 來 コ ノ た か わ らび 屬 ハ た い わ ん た か わ ら び 屬(Dicksonia)等 ト共 ニ た い わ ん た

か わ ら び 族(Dicksonieae)ニ 編 屬 セ ラ ル ル モ ノ ナ ル ガ 、後 屬 ノ莖 ノ 中 心 柱 ニ ハ 厚 膜

組 織 ヲ 伴 フ ヲ 以 テ 、 両 屬 ヲ 同 一 族 ニ編 入 シ ヲ ク ヨ リハ 、 寧 ロ た か わ らび 属 ヲ コ ノ族 ヨ リ分 離 シ テ た か わ らび 族(Cibotieae)ナ ル 一族ヲ設 ケ テ 之 ニ編 入 セ シ メ ン ト ス 。

し らね あ ふ ひ屬 並 ニ ソ ノ近 似 属 ノ構 造 ト類 縁*

熊 澤 正 夫

M. KumAzAwA: Structure and Affinities of Glaucidizan and its Allied Genera.

し ら ね あ ふ ひ 屬(Glauciaiorm),ひ ど ら す ち す 屬(HryarCtstis),み や を さ う 屬(Podo-

Phyllum),さ ん か え ふ 屬(Diphylleia)ノ 四 屬 ノ 植 物 二 就 キ テ ハ 、 ソ レ 等 ノ形 態 、生 態

* Contributions to Morphology and Genetics from the Departments of Plant- Morphology and of Genetics, Botanical Institute, Faculty of Science, Tokyo Imperial University, No. 96