DICOTYLEDONS. 163 



subtended by an involucre, and the divisions of the compound 

 umbel by involucels ; calyx tube adnate to the ovary, trun- 

 cate or minutely 5-toothed ; petals and stamens 5, inserted in 

 tlie disk at the top of the calyx tube ; ovary 2-celled, styles 

 2, distinct ; fruit of 2 carpels which separate from each other 

 at maturity, each carpel with 5 longitudinal ribs, and often 4 

 additional ribs between them ; oil tubes are usually present 

 under or between the ribs. [The flowers are all so much 

 alike, and the foliage varies so widely in species of the same 

 genus, that the characters for classification depend almost 

 wholly upon minute structural peculiarities of the fruit, 

 making the family an exceedingly difficult one for study. 

 There are about 27 genera and 51 species in our region, but 

 most of them flower late in the season.] 



I. DAUCUS. 



Annual or biennial herbs; leaves pinnately decompound, 

 the divisions finely dissected and linear ; umbels compound, 

 the outer rays longer; flowers white or pink, involucre of 

 ])innately dissected leaflets, involucels bract-like, entire or 

 tootlied; calyx teeth minute or wanting; petals obovate ; car- 

 pels obovate, ribs 9, })rickly or bristly, oil tubes 6. 



I). iTsiLLTs Miclix. Wild Carrot. Stem erect, simple or with 

 a few branches above, roii<;li-his]>id, 1-2 ft. high; k»aves twice ])iii- 

 iiate, divisions hnear; uinlu'ls loiii;-])e<IuiK'le(l, markedly concave on 

 the top; bristles of the fruit barbed or hooked, adhering readily to 

 hair and clothing. .Iune-.Inly. On dry, sterile soil, often a trouble- 

 some weed. 



II. PASTINACA. 



Biennial or sometimes annual, from a straight, fleshy root ; 

 stem erect, widely branched above; leaves j)innate; umbels 

 compound, involucre and involucels none ; flowers yellow ; 

 calyx teeth none ; fruit flattened dorsally ; lateral ribs winged, 

 the others inconspicuous. 



