Family 3. CYMODOCEACEAE 
By NorMAN TAYLOR 
Submerged marine perennials. Rootstocks creeping, often rooting and 
articulated at the joints. Leaves all linear and grass-like, acute ot obtuse at 
the apex, sheathing at the base. Flowers monoecious or dioecious, solitary or 
cymose, naked or rarely with minute hyaline bracts subtending the flowers. 
Staminate flowers of 2 long-pedicelled anthers equally or unequally attached. 
Anthers 2-celled, longitudinally dehiscent. Pistillate flowers of 2 united 
carpels, or of 1 carpel, sessile or sometimes stipitate. Style long or short, 
crowned with 1 or 2 thread-like stigmas. Mature fruit nut-like, 1-seeded. 
Seeds with a thick test, compressed or swollen. Embryo ovoid or ellipsoid, 
conforming to the shape of the seed. 
Leaves terete or semi-terete, anthers equally attached, stigmas 2. 1. Cymopoczga. 
Leaves flat, anthers unequally attached, stigma solitary. 2. HALODULE. 
1. CYMODOCEA Konig, Ann. Bot. K. & S. 2: 96. 1805. 
Submerged acaulescent, marine perennials, with creeping rootstocks. Leaves grass-like, 
terete in our species, acute at the apex and sheathing at the base, the sheaths more or 
Jess auriculate. Flowers dioecious, solitary or in simple or dichotomous cymes. Staminate 
flowers consisting of 2 anthers on the end of a long pedicel, the anthers equally attached, 
both the same height, 2-celled. Pistillate flowers of 2 carpels. Style crowned by 2 long, 
hair-like stigmas. Fruit a drupelet or nutlet, 1-seeded. Seeds pendulous, ovoid or oblong. 
Embryo conforming to the shape of the seed. 
Type species, Cymodocea aequorea Konig. 
1. Cymodocea manatorum Aschers. Sitz.-ber. Ges. Nat. Freunde Berlin 
1868: 19. 1868.— Bot. Zeit. 26: 512. 1868. 
Rootstock creeping, branching and rooting at the nodes; leaves all submerged, linear, 
terete or semi-terete, 4-35 cm. long, 0.8-2 mm. wide, acute or obtuse at the apex, ligulate 
at the base; stipular sheaths completely surrounding the leaf-bases, scarious, 1-4.5 cm. 
long ; staminate flower consisting of 2 anthers at the end of a long pedicel; anthers 2-celled ; 
pistillate flower of united carpels, without perianth, but subtended by a hyaline, perianth- 
like bract; style short; stigmas 2, slender; mature fruit 1-seeded, 3 mm. long and beaked 
by the persistent style. 
TYPE LOCALITY: Cuba. 
DISTRIBUTION : Bermuda and Florida to Cuba and Martinique. 
2. HALODULE Endl. Gen. 1368. 1841. 
Diplanthera Thouars (Gen. Nov. Madagasc. 3; hyponym. 1806); Steinh. Ann. Sci. Nat. II. 9: 
98. 1838. Not Diplanthera Banks & Solander. 1810. 
Submerged marine perennials, with creeping rootstocks. Rootstocks articulated and 
rooting at the nodes. Leaves all linear, grass-like, more or less sheathing at the base. 
Flowers dioecious. Perianth none. Staminate flower consisting of 2 anthers attached to 
the end of a long pedicel, the pedicels sheathed at the base. Anthers unequally attached, 
one higher than the other, 2-celled. Pistillate flowers consisting of a single naked carpel. 
Style short, crowned with a slender, solitary stigma. Mature fruit small, globose. 
Type species, Diplanthera tridentata Steinh. 
VoLume# 17, Part 1, 1909] 31 
