DA VALLIA. 



113 



fronds from rhizomes (prostrate stems) that are usually wide- creeping, scaly, 

 and peculiarly predisposed to remain on the surface of the soil. The fronds 

 are either simple (undivided), like those of B. lieterophylla ; pinnatifid (divided 

 half-way to the midrib), hke those of D. pedata; or more or less branched, 

 hke those of the popular D. divaricata (commonly called D. polyantha). As 

 regards size, the fronds may be only 2in. or Sin. long, including the stalks, 

 as is the case in the fully-developed ones of that Bornean little gem D. parvula, 

 or they may attain as many feet, as is the case in the handsome and highly 

 decorative D. pallida {D. Mooreana of gardens). It is mostly on these 

 external characters that the genus has been subdivided into the following 

 sections, all of which have been retained in the " Synopsis Fihcum " : 



AcEOPHOKUS (Ac-roph'-or-us), Moore. A division which contains plants 

 with characters deemed sufficiently distinct to be classified separately by Hooker 

 and Baker under the headings of Leucostegia and Odontoloma. 



EuDAVALLiA (Eu-dav-ar-li-a), Smith. This is the most extensive division 

 of the genus ; it is composed of a well-marked group of plants, all of which 

 more or less closely resemble one another except in dimensions. All have 

 ample fronds, deltoid (in shape of the Greek delta, A), tri- or quadripinnatifid 

 (three or four times divided half-way to the midrib), and of a leathery texture. 

 These species have their head-quarters in Polynesia and in South- Eastern 

 Asia, and are entirely absent from the New World. They are distmguished 

 by their semi- cylindrical or half- cup -shaped involucre (covering), which is of 

 a leathery texture and attached at the sides as well as at the base. There 

 are two sub-divisions : 



A. Prosaptia (Pros-ap'-ti-a), Presl. A small group of Ferns, having 

 the habit of Lomaria {Blechnum) Spicant, and in which the involucre 

 is quite homogeneous with the texture of the frond. 



B. Scyp'ularia (Scyph-ul-a'-ri-a), Fee. A small group of plants with 

 fronds simply pinnate (once divided to the midrib), having only a 

 few hnear (long and very narrow) segments, 4in. to 6in. long, Jin. to 

 fin. broad, and nearly entire. 



HuMATA (Hum-a'-ta), Cavanilles. All the plants belonging to this section 

 have fronds of a leathery texture, usually deltoid (in shape of the Greek 

 delta. A), Sin. to 6in. long, more or less distinctly dimorphous (of two forms), 

 the barren ones hardly more than once pinnatifid. Their involucres, of a 



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