台灣植物誌 第二版 Flora of Taiwan, 2nd edition Vol. 1
24. ASPIDIACEAE 三叉蕨科
TSAI, JINN-LAI and SHIEH, WANG-CHUENG
Terrestrial ferns, a few growing in crevices of rocks; rhizomes creeping or suberect; rhizome and stipe scales usually long and brown, narrowly linear. Fronds pinnate to decompound; stipes usually with a ring of vascular bundles (with only 2 bundles in Quercifilix), stipes and rachis grooved, the rachis grooves not open to rachilla grooves; upper side with ctenitis hairs along rachis, rachillae and costae in nearly all taxa; veins anastomosing in most genera, with at least one row of costal areolae, the areolae often with included veinlets, some genera with free venation. Sori usually round, dorsal on veinlets, on a plexus of veinlets, or terminal on a veinlet within an areola; in two genera (Hemigramma and Quercifilix) the sporangia follow the veins, becoming acrostichoid; indusia usually present, sometimes fugacious, round-reniform.
A family of about 20 genera with over 800 species, cosmopolitan, 9 genera in Taiwan.
KEY TO GENERA
1. Fronds dimorphic; sporangia acrostichoid.
2. Rhizomes stout, suberect; fronds glabrous, having a trilobed apex… 3. Hemigramma
2. Rhizomes creeping; fronds with hairs, not trilobed at apex… 8. Quercifilix
1. Fronds monomorphic; sporangia not acrostichoid.
3. Laminar margins with a tooth in each sinus, the teeth elevated on adaxial surface.
4. Veins anatomosing… 6. Pleocnemia
4. Veins free… 7. Pteridrys
3. Laminar margins without the teeth.
5. Veins anatomosing… 9. Tectaria
5. Veins free or with only a few veins anastomosing in fertile fronds.
6. Costae and costules densely scaly in abaxial surfaces… 1. Ctenitis
6. Costae and costules densely hairy or also bearing a few scattered scales in abaxial surfaces.
7. Rhizomes short, erect; rachis covered with hairs at upperside… 2. Ctenitopsis
7. Rhizomes short-creeping; rachis without hairs.
8. Rachis and rachillae both surfaces pubescent, without ridges on upper side; hairs unicellular… 4. Hypodematium
8. Rachis and rachillae usually hairy in grooves, with ridges on upper side; hairs multicellular… 5. Lastreopsis
1. CTENITIS C. Chr. 肋毛蕨屬
Terrestrial ferns; rhizomes short, stout, ascending to erect, scaly. Fronds subtufted, bipinnatifid to decompound, broadest at base, all pinnae catadromous branching except for the basal pair; veins free; rachis and rachilla scaly on underside, covered with multicellular brown "ctenitis hairs" on upperside, the rachis grooved on upperside but not open to rachilla grooves. Sori round, dorsal on veinlets; indusia round-reniform, attached on side opposite the pinna or pinnule apex, often fugacious, sometimes absent.
About 150 species, mostly tropical and subtropical, six in Taiwan.