Family 2. CERATOPTERIDACEAE 
By Rapa Curtiss BENEDICT 
Aquatic or semi-aquatic plants of tropical or sub-tropical regions. Stem 
creeping, sparsely scaly, reduced, rootless, the roots borne on the stipes. Leaves 
alternate, successive, viviparous, soft-herbaceous, dimorphic, the venation reticu- 
late, without included veinlets, the sterile leaves floating or emergent, the 
sporophyls taller, erect, 2-5 times pinnately divided the ultimate segments 
linear, with the margins evenly and narrowly revolute, often meeting along the 
midvein, and including 2 or 3 rows of narrow areolae. Sporangia abaxial, scat- 
tered in 1 or 2 lines along the longitudinal veinlets, thin-walled, globose, nearly 
sessile, the wall-cells sinuate, containing chlorophyl, the annulus few-celled 
(4-10), or many-celled (20-70) and with 8-10 lip-cells. Spores ephemeral, 
triplanate, the inner (cleavage) faces smooth, the outer portion rounded and 
regularly marked with three series of anastomosing ridges. 
1. CERATOPTERIS Brongn. Bull. Soc. Philom. 1821: 186. 1821. 
Teleozoma R. Br.; Richards. in Franklin, eae 767. 1823. 
Ellebocarpus Kaulf. Enum. Fil, 147. 1824 
Parkeria Hook. Exot. Fl. pl. 147. 1825. 
Furcaria Desv. Mém. Soc. Linn. Paris 6: 292. 1827. 
Characters of the family. 
Type species, Acrostichum thalictroides I. 
Lamina of the mature sterile leaves usually oblong; spores 32; annulus and 
lip-cells well-developed. 1. C. thalictroides. 
Lamina of the sterile leaves broadly deltoid or pentagonal. 
Spores 16; annulus and lip-cells well-developed; mature sterile leaves 
emergent, the lamina broadly deltoid, 25-40 cm. tong, 2-pinnate. 2. C. deltoidea. 
Spores 32 ; annulus few- celled, lip-cells wanting ; mature sterile leaves float- 
ing, the lamina pentagonal, not more than 20cm. long, 2-4-pinnatifid. 3. C. pleridoides. 
1. Ceratopteris thalictroides (1,.) Brongn. Bull. Soc. 
Philom. 1821: 186. 1821. 
Acrostichum thalictroides I,. Sp. Pl. 1070. 1753. 
Pteris thalictroides Sw. Jour. Bot. Schrad. 18002: 65. 1801. 
Teleozoma thalictroides R. Br.; Richards. in Franklin, Journey 767. 1823. 
Furcaria thalictroides Nesv. Mém. Soc. Linn. Paris 6: 292. 1827. 
Leaves slender, erect, strict, 6-75 cm. long, the stipes slender, 4-27 cm. long; lamina 
of the sterile leaf narrowly deltoid or oblong, 3.5-28 cm. long, 2-13 cm. broad, 1-2-pinnate- 
pinnatifid, the pinnae ovate-lanceolate, the segments linear-lanceolate or oblong, acute, 
1-2.5 cm. long, 2-5 mm. broad ; sporophyls taller than the sterile leaves; the lamina oblong, 
2-5-pinnately divided, the pinnae and smaller divisions distant, the ultimate segments 
flagelliform, 1-5 cm. long, the margins of the ultimate and penultimate divisions narrowly 
revolute, covering 1-2 rows of areolae and sporangia; sporangium with well-developed an- 
nulus and lip-cells ; spores 32. 
TypE LocaLiry: Ceylon. 
DISTRIBUTION: Jamaica; widely distributed in the Old World tropics. 
ILLUSTRATIONS: L,. Amoen, Acad. 1: pl. 12, 7.3; Bull. Torrey Club 36: 468. 7. 7. 
2. Ceratopteris deltoidea Benedict, Bull. Torrey Club 36: 472. 1909. 
Plants always partly submerged ; leaves up to 65 cm. long, the stipe flattened, not bul- 
bous; sterile leaves 15-45 cm. long, floating and emergent; lamina of the earliest leaves 
VOLUME 16, Part 1, 1909] 29 
