Davalliaceae

Araiostegia pseudocystopteris, photographed by Stephen McDaniel.

Belongs within: Pteridales.

The Davalliaceae is a family of mostly epiphytic ferns found in tropical and warm-temperate parts of the Old World.

Characters (from Kramer 1990): Epiphytic, less often epilithic or terrestrial ferns with short- to long-creeping, fleshy stem; cortex little sclerotic; stele a peculiar type of strongly dorsiventral dictyostele, only some perforations associated with leaf traces. Stem densely and permanently clothed in scales with often cordate or peltate base, the scales often toothed, sometimes clathrate; surface and/or margin of scales bearing hairs, these glandular or not; rarely hairs on stem beside scales. Roots mostly ventral. Leaves inserted in two alternate rows on dorsal side of stem, on short phyllopodia, with a functional articulation at base of petiole. Petiole more or less sclerotic, with two lateral, almost continuous pneumatophores, with two large adaxial and a varying number of smaller abaxial bundles (in some species only one or none), all together forming a U or a semi-circle; petiole usually long, stramineous to brown, adaxially flattened or more often with a groove, this continuous with grooves on axes of higher order, middle of groove usually raised, ridge-like. Lamina mostly simply pinnate to several times pinnate + pinnatifid, rarely simple, occasionally weakly to strongly dimorphic; axes adaxially grooved, grooves with raised centre; edges of laminal parts continuous with ridges (wings) bordering axis groove; costae and costules adaxially convex. Lamina often firm in texture, usually triangular, less often narrowed at base, when mature mostly without macroscopical epidermal appendages; dissection pattern anadromous or occasionally catadromous or isodromous. Ultimate free divisions dentate to pinnatifid, less often entire. Veins pinnately branched, free, ending behind margin, rarely reaching it; costae adaxially not grooved; "false veins" occasionally present between true veins. Stomata polocytic. Sori terminal on anterior fork of a vein, or situated in the fork (but one of the branches may be reduced), near the margin, nearly always uninerval, isodiametric or longer than wide; indusium attached at base, often also at sides or part of them, rarely reniform, with a short point of attachment, or absent; outer edge free, equalling margin or not; segments not rarely protracted into small projections flanking sori. Soral trichomes present or not. Receptacle not elevated; sporangia long-stalked, stalk proximally 1- or 2-seriate, distally 3-seriate. Annulus vertical, indurated part not reaching stalk or stomium. Spores monolete.

Davalliaceae
    |--Gymnogrammitis dareiformis (Hooker) Ching ex Tard. & Christensen in Lecomte 1939 (see below for synonymy) I88
    |--Leucostegia immersa (Wallich) Presl 1836 [=Davallia immersa Wallich ex Hooker 1846] I88
    |--Davallodes membranulosum (Wallich) Copel. 1927 (see below for synonymy) I88
    |--Pachypleuria I88
    |--Davallia SS04
    |    |--D. clarkei Baker in Hooker & Baker 1874 SS04, I88 [=Araiostegia clarkei (Baker) Copel. 1927 I88]
    |    |--D. denticulata SS04
    |    |--D. griffithiana Hooker 1846 [=Humata griffithiana (Hooker) Christensen 1931] I88
    |    |--D. novae-zealandiae C45
    |    `--D. trichomanoides Blume 1828 [incl. D. bullata Wallich ex Hooker 1846] I88
    `--Araiostegia I88
         |--A. beddomei (Hope) Ching 1959 [=Davallia beddomei Hope 1899] I88
         |--A. delavayi (Bedd.) Ching 1959 [=Davallia pulchra var. delavayi Bedd. ex Clarke & Baker 1888] I88
         |--A. hookeri (Moore) Ching 1959 (see below for synonymy) I88
         |--A. multidentata (Hooker & Baker) Copel. 1927 (see below for synonymy) I88
         |--A. pseudocystopteris (Kunze) Copel. (see below for synonymy) I88
         `--A. pulchra (Don) Copel. 1927 [=Davallia pulchra Don 1825, Leucostegia pulchra (Don) Smith 1842] I88

Araiostegia hookeri (Moore) Ching 1959 [=Acrophorus hookeri Moore ex Bedd. 1865, Leucostegia hookeri (Moore) Bedd. 1883] I88

Araiostegia multidentata (Hooker & Baker) Copel. 1927 [=Davallia multidentata Hooker & Baker 1867, Leucostegia multidentata (Hooker & Baker) Bedd. 1876] I88

Araiostegia pseudocystopteris (Kunze) Copel. [=Davallia pseudocystopteris Kunze 1850, D. pulchra var. pseudocystopteris (Kunze) Clarke 1880, Leucostegia pseudocystopteris (Kunze) Bedd. 1876] I88

Davallodes membranulosum (Wallich) Copel. 1927 [=Davallia membranulosa Wallich ex Hooker 1846, Araiostegia membranulosa (Hooker) Holtt. ex Sen, Sen & Holtt. 1972, Leucostegia membranulosa (Wallich) Smith 1875] I88

Gymnogrammitis dareiformis (Hooker) Ching ex Tard. & Christensen in Lecomte 1939 [=Polypodium dareiforme Hooker 1860, Araiostegia dareiformis (Hooker) Copel. 1931, Davallia dareiformis (Hooker) Levinge ex Clarke 1880] I88

*Type species of generic name indicated

REFERENCES

[C45] Colenso, W. 1845. Memoranda of an excursion, made in the Northern Island of New Zealand, in the summer of 1841-2; intended as a contribution towards the natural productions of the New Zealand groupe: with particular reference to their botany. Tasmanian Journal of Natural Science 2: 210-234.

[I88] Iwatsuki, K. 1988. An enumeration of the pteridophytes of Nepal. In The Himalayan Plants vol. 1 (H. Ohba & S. B. Malla, eds) The University Museum, University of Tokyo, Bulletin 31: 231-339.

Kramer, K. U. 1990. Davalliaceae. In: Kramer, K. U., & P. S. Green (eds) The Families and Genera of Vascular Plants vol. 1. Pteridophytes and Gymnosperms pp. 74-81. Springer.

[SS04] Schneider, H., E. Schuettpelz, K. M. Pryer, R. Cranfill, S. Magallón & R. Lupia. 2004. Ferns diversified in the shadow of angiosperms. Nature 428: 553-557.