UMBELLIFER^ 533 



whole cavity and is usually adnate to the pericarp; the inner 

 seed faces may be concave or flat. There is considerable 

 oily endosperm present in the seed. The small embryo is 

 imbedded in the endosperm near the hilum. The fruit is of 

 greater taxonomic importance than any other portion of the 

 plant. Usually, it is necessary to have the mature fruit 

 before an accurate determination can be made of a species in 

 hand. Keys to the genera and species are largely based upon 

 fruit characters. 



Geographical. — The carrot family is one of north temperate regions, not 

 being well represented in the tropics. According to Britton and Brown, there 

 are close to 1,600 species in about 170 genera. 



Key to Genera of Economic Importance 



Fruit bristly, Dauciis (carrot). 

 Fruit not bristly. 



Fruit strongly flattened dorsally, with lateral ribs more or less prominently 



winged (Fig. 218, F), Pastinaca (parsnip). 

 Fruit not strongly flattened dorsally, usually more or less laterally flattened 

 (Fig. 222, B). 

 Stylopodium conical. 



Involucre wanting; leaves pinnately compound. 

 Flowers white. Coriander (coriander). 

 Flowers yellow, Ftenictdum (fennel). 

 Involucre present; leaves ternately compound, Canim (caraway). 

 Stylopodium flat or wanting, Apiiim (celery and parsley). 



DAUCUS CAROTA (Carrot) 



Habit, Root and Stems. — The common carrot is usually a 

 biennial, sometimes, however, running to seed the first year. 

 During the first season of growth, there is a storage of food in 

 the enlarged hypocotyl and prominent tap root, both of which 

 become fleshy, forming the so-called "carrot." Four longi- 

 tudinal rows of secondary roots are given off from the tap 

 root. The roots are much thinner and woodier in the wild 

 form of the carrot than in cultivated forms. 



