(A, B, after Raciborski; C, after Hooker; D, E, after Goebel.)

Gleichenia is represented by several species in the tropics and extends to south temperate and Antarctic latitudes. The species G. dichotoma (= G. linearis) is one of the more successful tropical ferns, while G. moniliformis (by some authors recognised as a distinct genus, Stromatopteris) is peculiar to New Caledonia. The monotypic genus Platyzoma is a xerophilous Australian fern. The Gleicheniaceae are unrepresented in existing north temperate floras.

Matonineae. (Matonia.)

The genus Matonia, placed in the Cyatheaceae by Sir William Hooker and compared by other authors also with the Gleicheniaceae, is now included in a special family. The sori are circular and consist of 5–11 large sporangia ([fig. 224], E, G) sessile on a central columnar receptacle which spreads out into an umbrella-like indusium (D, i) with its incurved margin tucked in below the ring of sporangia. The indusium is detached when the sporangia are ripe. The annulus is oblique and incomplete and often slightly sinuous; it agrees in the main with that of Gleichenia. The species Matonia pectinata is characterised by dichotomously branched fronds (figs. [227], [228]) with long and slender petioles; the pinnae bear linear pinnules with forked lateral veins and occasional lateral anastomoses ([fig. 224], F). The only other living representative is M. sarmentosa, discovered by Mr Charles Hose at Niah, Sarawak[688]: this species has long pendulous leaves apparently very different from those of M. pectinata, but the branching of the frond may be regarded as a modification of a primitive form of dichotomy[689]. A small bud occurs in the angle between the forked linear segments and the rachis, as in some species of Gleichenia[690]. Matonia is confined to the Malay region: M. pectinata grows in Western Borneo and in various localities in the Malay peninsula, while M. sarmentosa, has been found in one locality only; the latter species has recently been transferred to a new genus Phanerosorus, but in view of the practical identity in anatomical structure and the close agreement as regards the sori of the two species there would seem to be no justification for this change of name[691].

Fig. 227. Matonia pectinata. (⅕ nat. size.) M.S.

Loxsomaceae.

The New Zealand genus Loxsoma has marginal sori with a cup-like indusium surrounding an elongated receptacle bearing pear-shaped sporangia provided with a complete oblique annulus. The genus is chiefly interesting because of its isolated position; it agrees with Trichomanes (Hymenophyllaceae) in the structure of the sorus and with species of Dicksonia and Davallia in habit; it shows some resemblance also to Gleicheniaceae and Schizaeaceae[692]. A new type of fern described by Christ[693] from Costa Rica as Loxsomopsis costaricensis affords a striking instance of discontinuous distribution and emphasises the antiquity and generalised features of the family.