AMMIACEAE. 311 



cylindric or conic-subulate, stigmatic above the middle. Fruit bony, 3-4-celled, 

 with 1 seed in each cavity. [Middle Latin, forward-creeping.] Four known 

 species of North and Central America and the West Indies. Type species: 

 Proserpinaca palustris L. 



1. Proserpinaca platycarpa Small, Bull. N. Y. Bot. Gard. 3: 432. 1905. 



Perennial, glabrous, 1-3.5 dm. long, densely leafy. Leaves oblong or 

 elliptic, 1.5-5.5 cm. long, sharply serrate; flowers solitary and sessile in the 

 axils; calyx wing-angled, its deltoid teeth about 1 mm. long; fruit 45 mm. 

 wide, constricted above the middle,, its 3 angles dilated. 



Fresh-water swamps and sink-holes, Great Bahama, New Providence, Eleuthera 

 and Cat Island. -Florida. Recorded by Schoepf as P. palustris L. SOUTHERN 

 MERMAID-WEED. 



Order 22. AMMIALES. 



Herbs, shrubs or trees, almost always with petaliferous flowers. Calyx- 

 segments and petals' usually 5. Stamens 4 or 5. Ovary inferior, adnate 

 to the calyx, compound; ovules 1 in each cavity. 



Family 1. AMMIACEAE Presl. 

 CARROT FAMILY. 



Herbs, with alternate compound or sometimes simple leaves, the petioles 

 often dilated at the base. Stipules none, or rarely present and minute. 

 Flowers small, generally in compound or simple umbels, rarely in heads or 

 capitate clusters, often polygamous. Umbels and umbellets commonly 

 involucrate or involucellate. Calyx-tube adnate to the ovary, its margin 

 truncate or 5-toothed, the teeth seldom conspicuous. Petals 5, inserted on 

 the margin of the calyx, usually with an inflexed tip, often emarginate or 

 2-lobed, those of the outer flowers sometimes larger than those of the inner. 

 Stamens 5, inserted on the epigynous disk; filaments filiform; anthers 

 versatile. Ovary inferior, 2-celled ; styles 2, filiform, persistent, often borne 

 on a conic or depressed stylopodium; ovules 1 in each cavity, pendulous, 

 anatropous. Fruit dry, composed of 2 carpels (mericarps), which gen- 

 erally separate from each other at maturity along the plane of their con- 

 tiguous faces (the commissure). Fruit either flattened laterally (at right 

 angles to the commissure )_, or dorsally (parallel to the commissure), or 

 nearly terete (not flattened). Carpels after parting from each other sup- 

 ported on the summit of a slender axis (the carpophore), each with 5 

 primary ribs in their pericarps (rarely ribless), and in some genera with 4 

 additional secondary ones, the ribs or some of them often winged. Pericarp 

 membranous or corky-thickened, usually containing oil-tubes between the 

 ribs, or under the ribs and on the commissural sides, sometimes irregularly 

 scattered, sometimes none. Seeds 1 in each carpel, usually adnate to the 

 pericarp ; seed-coat thin ; endosperm cartilaginous ; embryo small, placed 

 near the hilum ; cotyledons ovate, oblong or linear. About 170 genera and 

 1600 species, of wide distribution. The mature fruit is necessary for the 

 certain determination of most of the genera and many of the species. 



