818 APPENDIX. 22. DRYOPTERIS. 



hairs; costulae (main veins) pinnate in the ultimate lobes. Sori numerous, 

 minute, in rows near the costae (central ribs of tbe tertiary segments), 1 — ^ 

 on each lobe ; indusium minute, membranaceous, whitish, soon hidden among 

 the capsules, visible by ± 50 X magnifying power. — Mr. C. A. Backer found 

 this plant in the new vegetation of the small volcanic island Krakatau, which 

 was totally destroyed by an eruption in 1883. It may be a hybrid between 

 D. setigera, 0. Ktze and multiseta, C. Chr. or Phegopteris ornata, Fee. It 

 differs: a, from D. setigera in having the stipes and rachises provided with 

 deciduous, subulate scales with persistent, rough bases; b, from D. multiseta 

 in having a line of hairs on the upper side of stipes and rachises; c, from 

 Phegopteris ornata in having the fronds much smaller, vdth the rachises not 

 winged and the sori minutely indusiate. 



Vap. asperai : Differs from Mr. Backer's plant in having the rachises 

 not beset with deciduous, flat, subulate scales, but with + persistent, subu- 

 late, subterete bristles of the same colour, the pinnulae horizontally spreading, 

 the tertiary segments rather small, with the edges much recurved when dry. 

 Indusium somewhat larger, visible by + 15 X magnifying power, but also 

 hidden among the capsules. Rhizome creeping. — Perhaps a distinct species. 



Krakatau; — var. aspera: Java (Preanger Regencies, Zippelius N". 268). 



§ 2. NEPHRODIUM. 



* (65) D. pteroides, O.Xtze. — Insert as a synonym: Polypo- 

 dium pteroides. Rets, (oldest name). 



(66a) D. mindanaensis, Cht-igt, Philipp. Journ., II., 194. 



Rhizome creeping or very oblique. Stipes distant, + 50 c.M. long, 

 plumbeo-rufous, short-puberulous like the whole plant, the base clothed with 

 brown, .opaque, ovate, acuminate scales. Fronds + 70 c.M. long, + 40 c.M. 

 broad, ovate-acuminate, caudate, not or hardly narrowed at the base. Pinnae 

 + 28 on each side below the incised apex, spreading, tolerably approximate, 

 sessile, not naiTowed at the base, + ^% c.M. broad, caudate-acuminate, the 

 edge cut to Vj-way down to the costa. Lobes + 45—50 on each side, close, 

 pectinate, subfalcate, obtuse but mucronulate, nearly without sinuses between 

 them, + % C.M. long, + «/a c.M. broad. Texture herbaceous; colour bright- 

 green, opaque; veins stramineous and densely white-puberulous, as are the 

 costae, + 10—12 on each side, simple, 1—2 lower anastomosing. Sori 5—8 

 on each side; indusium flaccid, grey, ciliate. 



Mindanao. 



