of entire bracts. I Fr. scarcely compressed, ^ with bristly ribs. . Osinorhiza. 27 



•284 LXVII. UMBELLIFER^. Htdrocottle. 



Cafispectus of the Genera. 

 * Plants native or naturalized. 



^ Seeds flattish inside. Sitmi. 8 



C Fr. laterally compressed. ( Seeds grooved inside. Conium. 28 



^ Petals radiant. . Heracleum. 23 



{ Fr. dorsally compressed. I Petals all equal. . Conioselinum. 18 



S with smooth ribs. . Ligusticiim. 17 



I w ith bristly ribs. . Osmorhiza. 27 



\ Rays 2—4. . . Sanicula. 3 



^ Fr. verj- bristly, i Rays many. . . Daucus. 23 



< several. ^ Fruit not bristly Discopleiirum. 5 



_ rinvolucre lof cleft bracts, (one only, bipinnatitid Erigenia. 29 



§ ] I Cal. limb s Leaves 3-parted, . . Ctijptotccnia. 9 



u I < obsolete. ^ Leaves finely divided. . Charapfiyllum.QB 



S js < rFr. laterally compressed. ( Caly.x limb 5-toothed. . . Cicuta. 7 



.« r ^ ) |> the niari,'in singly winged. . . Archemora. 21 



^ g 1 Fr. dorsally compressed, ^ the margin doubly winged. . . Archangelica. 20 



£ I t3 Linvoluc.O. I Fruit scarcely compressed, ovoid-globose JEthvMa. 16 



%\. S Lvs. linear. . Crantzia. 2 



o ^ with 4—30 pedicellate or subsessile flowers. \ Lvs. roundish. Hydrocotyle. 1 



E I Umbels simple, J densely capitate, with 50 or more sessile flowers. . . . Eri/ngium. 4 



I Carpels with 5 winged ribs Thaspiu7n. 15 



^ Carpels with 5 filiform ribs Zizia. 10 



( Involucels minute. ( Carpels smooth, ribs obsolete. . . . Polytcenia. 24 



< Involucels very large. Leaves simrde, perfoliate Bup/eurum. 6 



Flowers yellow. ( Involucels 0. Fruit much compressed dorsally Pastinaca. 22 



* * Cultivated exotics, not naturalized. 



i Fruit laterally <t roundish. . Apium. 13 



C Petals all equal. < compressed, ^oval. . . Carum. 11 



^ Involucre 0, or < ( Fruit not compressed. . . Pimpinella. 12 



\ of 1 entire bract. ( Petals radiant Coriandrum. 30 



Uvhite. ( Involucre of a few cleft bracts Pelroselinum. li 



Flowers (yellow -. . . . Focnicuium. 19 



Suborder 1.— O RTHOSPERM^. 



The inner surface of the seeds and albumen flat or nearly so. 

 1. HYDROCOTtLE. 



Gr. vSiop, water, kotv^tj, a vessel ; the concave leaf often holds water. 



Calyx obsolete ; petals equal, ovate, spreading, entire, the point 

 not inflected ; styles shorter than stamens ; fruit laterally flattened, 

 the commissure narrow; carpels 3-ribbed, without vittae. — Herba- 

 ceous, creeping, usually aquatic plants. Umbels simple. Involucre few- 

 leaved. 



1. H. Americana. Penmjiforl. 



Smooth and .shining; st. fiJiform, procumbent; lvs. reniform-orbicular, 

 sli^irhtl}' lobed, crenate; umbels sessile, 3 — 5-flowered; //•. orbicular. — '4 A small, 

 delicate plant, growing close to the moist earth beneath the shade of other vege- 

 tables, Can. to S. Car. Stems branching, 2 — 6' long. Leaves thin, 1 — 2' diam., 

 on petioles 2 — 3' long. Flowers greeni.sh- white, small, nearly sessile, in sim- 

 ple, capitate, sessile, axillary umbels. Jn. — Aug. 



2. H. iNTERRUPTA. Muhl, (H. vulgaris. Michx.) 



Smooth ; lis. peltate, orbicular, crenate ; umbels capitate, proliferous, sub- 

 sessile, about 5-flowered ; fr. acute at base. — % In wet places. New Bedford, 

 Ma.ss. T. A. Greene, rare. Root and stem creeping. Leaves almost centrally 

 peltate, thin, 8—10" diam. Petioles 2—3' long. Peduncles longer than the 

 petioles. Flowers subsessile, in clo.se umbels which become whorls in inter- 

 rupted spikes by other umbels being successively produced on the extending 

 peduncle. Jn. 



3. H. UMBELLATA. Umbellate Pennywort. 



Smooth ; lvs. peltate, orbicular, crenate, emarginate at base, on long peti- 

 oles ; scapes about as long as the petioles; umbels sivcvpie, often proliferous; /s. 

 pedicellate. — %. In ponds and bogs, Mass. ! to La., rare. Stems creeping, often 

 submersed, .several inches long. Leaves 8—12" diam., notched at base so as to 

 appear rcniform. Petioles a iittle eccentric, and with the scapes slender, float- 

 ing or erect, and 4 — G' long. Umbels 20 — 30-flowered, the upper pedicel often 

 prolonged and umbellate. May— Jl. 



