88 ENGLISH BOTANY. 



OEDEE XXXIII— U MBELLIFER^. 



Herbs, generally with hollow furrowed stems ; more rarely 

 undcrshrubs. Leaves alternate, very rarely opposite, frequently 

 ternately- or pinnately-compound or -decompound, without dis- 

 tinct stipules, but usually with the leaf-stalk dilated at the base, 

 especially in the uppermost leaves. Inflorescence usually a com- 

 pound umbel (umbel), with the primary rays bearing small simple 

 umbels (umbellules), more rarely a simple umbel ; umbels usually 

 surrounded by whorls of small leaves (involucres) and umbellules 

 {involiicels) by similar whorls. Elowers perfect or polygamous 

 (more rarely all unisexual), regular, or radiant by having the outer 

 petals of the exterior flowers larger, generally white, yellow, or 

 greenish. Calyx of 5 sepals, completely combined and adnate to 

 the ovary, with the limb reduced to a ring, more rarely 5-toothed. 

 Petals 5, frequently with the apex inflected so as to appear notched, 

 inserted round a fleshy disk which crowns the ovary. Stamens 5. 

 Ovary adherent to the calyx, crowned with a fleshy epigynous disk, 

 divided into 2 cushions (stylopods), 2-celled, each cell with a soli- 

 tary suspended ovule ; styles 2, distinct. Pruit (cremocarp) 2-celled, 

 generally separating when ripe into 2 achenia (mericarps), which 

 are most commonly suspended from a more or less deeply cleft or 

 entire columella, sometimes termed the carpopliore. Each mericarp 

 has usually 5 ridges or ribs (primary ridges), and sometimes 4 

 intermediate ones (secondary ridges) ; generally there are also, in 

 the substance of the pericarp, small canals or tubes (vittcB) con- 

 taining essential oil. Seed anatropous ; albumen copious, horny ; 

 embryo minute. 



Tribe I.— HYDROCOTYLE^. 



Elowers generally in simple umbels or heads, or in 2 or more 

 whorls one above the other. Petals entire, acute, valvate. Cremo- 

 carp laterally compressed, without calyx-teeth at the apex ; colu- 

 mella none ; mericarps convex or keeled on the back ; primary 

 ridges usually unequal, the intermediate ones often obsolete and 

 the lateral ones remote from the margin, the secondary ridges 

 none ; interstices without vittse. Seed flat or keeled on the inner 

 side. 



