UMBELLIFER^. 



253 



The genera are difficult, as they have to rest mainly on the fruit .-iml seed : those are best ex- 

 amined in transverse slices. The whole order is divided into munurous tribes. These, beiii" 

 somewhat recondite, are here dispensed with. ' " 



I. Umbels simple, or irregularly or imperfectly compound, the flowers sessile or sli'ditly pedi- 



cellate. Oil-tubes none or obscure. ° 



* Leaves simple, not strongly lobed nor toothed : uniliels simple or proliferous : flowers white, 



without bracts : oil-tubes none. 



1. Hydrocotyle. Leaves peltate or orbicular. Fruit rounded, laterally compressed, smooth : 



ribs iililbrm. Creeping, aquatic or subacpiatic. 



2. Bowlesia. Leaves reriiform, opposite ! Fruit ovate, turgid and ribless, pubescent. 



* * Leaves spinosely toothed, or palmately lobed or pinnatifid : oil-tubes obscure. 



3. Eryngium. Leaves rigid, spinosely toothed. Flowers perfect, bracteate, sessile in dense 



heads, l)luish. Fruit covered with hyaline scales. 



4. Sanicula. Leaves lobed and incised. Flowers polygamous, in irregularly compound um- 



bels, mostly yellow. Fruit covered with hooked prickles or tubercles. 



II. Umbels regularly compound. Fruit without prominent secondary ribs and not furnished 

 with hooked or barbed prickles. Oil-tubes rarely wanting. 



* Fruit more or less compressed laterally, bi'oadly ovate or subglobosc to elliptic-oblong, not 



broadly winged. 

 -J- Seed terete, with involute margins : oil-tubes conspicuous : carpophore entire : flowers yellow. 



5. Deweya. Fruit oljlong or nearly orbicular ; ribs filiform or prominent : oil-tubes 2 or 3 in 



the intervals. 



+- +- Seed deeply sulcate on the face : oil-tubes wanting : carpophore 2-parted : flowers white. 



6. Conium. Fruit broadly ovate, with prominent equal obtuse ribs. 



-i- -1- -1- Seed nearly terete or but slightly concave on the face : flowers white. 



++ Fruit small, not prominently ribbed : oil-tubes solitary : stylopodium depressed : umbels 

 naked, sessile or nearly so. 



7. Apium. Fruit broadly ovate : seed not concave : carpophore entire. Biennial. 



8. Apiastrum. Fruit cordate : seed concave and longitudinally incurved : carpophore 2-parted. 



Annual. 



++ ++ Fruit not prominently ribbed : stylopodium more or less prominent : carpophore bifitl or 



2-parted. 



9. Carum. Fruit ovate or oblong : ribs filiform : oil-tubes solitary. Involucre and involucels 



usually present. Leaflets linear, entire. 



10. Pimpinella. Fruit ovate, with a broad commissure : ribs sliglitly prominent : oil-tubes 



numerous. Umbels nearly naked. Leaflets cuneate-ovate, pinnatifid. 



11. Berula. Fruit nearly globose, emarginate at base, with thickened epicarp : oil-tubes inimer- 



ous and contiguous. Involucre and involucels present. Leaflets ovate-oblong to linear, 

 laciniately toothed. 



++ ++ ++ Fruit with prominent corky wings, didymous : stylopodium depressed : carpophore 

 2-parted. Stout perennials, with involucels and often involucres also. 



12. Cicuta. Fruit broadly ovate, with thick obtuse wings : oil-tubes solitary. 



13. Slum. Fruit oblong or ovate : ribs wing-like : oil-tubes 2 or 3 in the intervals. 



* * Fruit somewhat compi-essed laterally, linear-oblong, with broad commissure, not winged ; 



seed sulcate or reniform in section : carpophore 2-parted, persistent : flowers white. 



14. Osmorrhiza. Fruit narrowly attenuate at base, hispid on the acutish angles: oil-tubes very 



obscure : seed sulcate on the face or somewhat involute. Umbels nearly naked. Leaf- 

 lets ovate, cleft and toothed. 



1,5. Glycosma. Similar ; fruit not attenuate at base, very rarely hispid : seed broadly sulcate. 



1(3. Podosciadium. Fruit not attenuate at base, glabrous : ribs filiform : oil-tubes solitaiy or 

 in pairs : seed reniform in section and longitudinally ridged on the face. Involucre and 

 involucels present. Leaflets linear. 



* * * Fruit not compressed, or more or less compressed dorsally, oblong to orbicular. 

 +■ Fruit not compressed : flowers white. 

 17. GBnanthe. Fruit oblong to globose : ribs corky and rounded, with very narrow intervals 

 and solitary oil-tubes. 



