92 SUMMARY or CURRENT RESEARCHES RELATING TO 



B. CRYPTO GAMIA. 



Cryptogamia Vascularia. 



Classification of Ophioglossacese.* — K. Prantl gives the following 

 characters of the primary subdivisions of the genera belonging to this 

 family : — 



I. BotrycMum. 



Sectio 1. Evhotrychium. Folia semper glaberrima, stomata in 

 utraque pagina obvia ; lamina oblonga vel deltoidea, ad sum- 

 mum bipinnata ; petioli fasciculi bini prseter binos in pedun- 

 culum exeuntes ; xylema rhizomatis indistincte seriatum. 5 sp. 

 Sectio 2. Phyllotrichum. Folia juvenilia ssepe et adulta 

 pilosa, stomata infera ; lamina deltoidea, bi- ad quinque- 

 pinnata ; xylema rhizomatis distincte seriatum. 10 sp. 

 II. Helminthostachys. 1 sp. (H. zeylanicum). 

 III. Ophioglossum. 



Sectio 1. Euophioglossum. Ehizoma hypogseum, prseter invo- 

 lucri margines glabrum, pedunculiis solitarius e petiolo vel 

 basi laminae oriundus, petioli fasciculi basi tres, intra laminam 

 plus minus ramosi, stomata utrinque obvia, rarius supra 

 parca vel nulla, radicis fasciculus monarchus. 27 sp. 

 Sectio 2. Ophioderma. Ehizoma epidendrum papillosum ; 

 pedunculus solitarius e lamina oriundus ; lamina fasciasformis 

 integra vel dichotome lobata, basi sensim in petiolum 

 teretem angustato, nervo mediano hinc inde laterales emit- 

 tente, petioli fasciculi numerosi, stomata utrinque obvia, 

 radicis fasciculus tri- ad tetrarchus. 1 sp. (0. pendulum). 

 Sectio 3. Cheiroglossa. Ehizoma epidendrum longepilosum ; 

 pedunculi plures, anteiiores e margine basali laminaa 

 dichotome lobatse oriundi, nervis dichotomis ; petioli fasci- 

 culi numerosi ; stomata infera ; radicis fasciculus diarchus. 

 1 sp. {0. palmatum). 



Structure of Helminthostachys.t — From an examination of 

 Helminthostachys zeylanica from Borneo, K. Prantl discusses the 

 relationship between this and the two remaining genera of Ophio- 

 glossacese. 



It is distinguished from both Ophioglossum and BotrycMum by its 

 dorsiventral horizontal rhizome, bearing two rows of leaves on its 

 dorsal and several rows of roots on the lateral and ventral sides. 

 Only a single leaf unfolds each year. The course of the fibrovascular 

 bundles resembles that in BotrycMum rather than in Ophioglossum ; 

 there is no median bundle ; but, on the contrary, there are four placed 

 diagonally to the base of the leaf-stalk. In the absence of any 

 sclerenchyma in the collateral structure of the bundles in the stem 

 and leaf, in the absence of palisade-parenchyma, and in other points, 

 Helminthostachys presents a complete agreement with the other two 

 genera. 



* Ber. Deutsch. Bot. Gesell., i. (1883) pp. 348-53. 

 t Ibid., pp. 155-61. 



