262 UMBELLIFER^. Hydrocotvle. 



Series 1. Orthosi'erm^, DC. Inner face of the seed and albumen plane, yieither convolute 



nor involute. 



Tribe I. HYDROCOTYLEjE. Spreng. ; DC. 

 'Fruit laterally compressed. Carpels convex or rarely acute on the hack: primary ribs 5, 

 sometimes obscure ; the lateral 07ies either marginal, or on the face of the comjnissure ; 

 intermediate ones most prominent : secondary ribs sometimes filiform, sometimes almost 

 or entirely wanting. Vittce seldom present. Seed flaltish on the face. — Umbels simple 

 or imperfectly compound. 



1. HYDROCOTYLE. Tourn. ; Lam. ill. «. 188 ; DC. prodr. 4. p. 59 ; Endl. gen. 4355. 



MARSH PENNY-WORT. 



[ From the Greek, hvilor, water, and cotyle, a cup ; the species grow in wet places, and the leaves of some of them arc a 

 little concave and stalked in the centre] 



Margin of the calyx obsolete. Petals ovate, entire, acute, spreading, straight at the point. 

 Fruit nearly orbicular, flattened laterally. Carpels without vittaj : primary ribs 5, filiform ; 

 the dorsal and lateral ones often obsolete ; intermediate ones enlarged. — Slender plants, 

 growing in wet places, with creeping stems and peltate or cordate leaves. Umbels simple. 

 Involucre few-leaved. Flowers sessile or pedicellate, white. 



1. Hydrocotvle Americana, Linn. American Marsh Penny-wort. 



Plant very smooth and shining ; leaves orbicular-reniform, slightly lobed and doubly cre- 

 nate ; umbels nearly sessile, 3 - 5-flowered ; fruit orbicular-ovate, 2-ribbed on each side. — 

 Linn. sp. 1. p. 234; Michx.fl. 1. p. 162 ; Pursh, fl. \. p. \Q2 ; A. Rich. Hydrocot. in ann. 

 sc. phys. 1820, 4. p. 184. t. 55. /. 10 ; Ell. sk. 1. p. 348 ; Torr. fl. 1. p. 303 ; Bigel. Jl. 

 Bost. p. 109 ; DC. prodr. 4. p. 64 ; Beck, hot. p. 140 ; Darlingt. fl. Cest. p. 183 ; Torr. 

 4- Gr.fl. N. Am. 1. p. 599. 



Stems very slender, branching, terete, with long suckers. Leaves thin, 1-2 inches in 

 diameter, palmately about 9-nerved : petiole as long as the lamina, inserted at the base of tlie 

 sinus. Flowers very small, greenish, often with a tinge of purple. Fruit scarcely a line 

 wide : ribs filiform : intervals smooth. 



Wet shady places ; common. Fl. July - August. Fr. September. 



2. Hydrocotyle umbellata, Linn. Mamj-Jlowered Marsh Penny-wort. 



Smooth; leaves peltate, orbicular, emarginate at the base, doubly crenate ; scape usually 

 longer than the petioles ; umbel 20 - 30-flowered, sometimes proliferous ; pedicels slender ; 

 fruit didymous, 2-ribbed on each side. — Linn. sp. 1. p. 234 ; Spreng. umb. p. 1. t. 1 ; Ell. 

 sk. 1 . p. 346 ; Torr.fl. 1. p. 303 ; Bigel. fl. Bost. p. 109 ; DC. prodr. 4. p. 60 ; Beck, hot. 



