Daucu*.] U3IBELLIFER.& 113 



2. HIPPURIS. Linn. Mare's- tail. 



Perianth single, superior, forming a very indistinct rim to the 

 germeu. Fruit, a small one-seeded Nut. Name from JTTTTGS, 

 a horse y and ovpa, a tail. Monandria. J\fonogynia. 



1. H, vulgaris, Linn. Common Mare's-tail. Leaves 6 8 or 

 10 in a whorl, linear. Br. Fl. 1. p. 2. E, FL v. i. p. 4. E. 

 Bot. t. 763, 



Ditches, sides of lakes and borders of slow streams, frequent. Fl. 

 May, June. %. Root creeping. Stem a foot or more above the 

 water, round, juicy, polished, reddish, with many whorls of spreading, 

 linear, entire, smooth, single-ribbed leaves. Fhwers small. Anther 

 red before it bursts. The lower leaves, deep under water, are Ion?, 

 thick-set, pellucid, and pale ; the herb in winter bearing no other. In 

 this state it is noticed by Dilleiiius as a remarkable variety. Smith. 



ORD. 33. UMBELLIFER^E. Juss. Umbelliferous Family. 



Calyx superior, either entire, or 5-toothed. Petals 5, inserted 

 on the outside of a fleshy disk ; usually inflexed at the point ; 

 aestivation generally valvate, very rarely imbricate. Stamens 

 5, alternate with the petals, incurved in aestivation. Ovarium 

 inferior, 2-celled, with solitary pendulous ovula; crowned by a 

 double fleshy disk ; styles 2, distinct ; stigmata simple. Fruit 

 consisting of 2 carpella, separable from a common axis, to which, 

 they adhere by their face (the commissure) ; each carpellum tra- 

 versed by elevated ridges, of which five are primary, and four 

 alternating with them, secondary ; the ridges are separated by 

 channels, below which are often placed, in the substance of the 

 testa, certain linear receptacles of coloured oily matter, called 

 vitta?. Seed pendulous, usually adhering inseparably to the pe- 

 ricarpiuni, rarely loose ; embryo minute, at the base of abundant 

 horny albumen ; radicle pointing to the hilum. Herbs. Stem, 

 oftenfistulose and farrowed. Leaves alternate, generally compound 

 and embracing the stem with their sheathing bases. Flowers um- 

 bellate, usually involitcrate. 



A most extensive and extremely important Natural Order, in- 

 cluding many poisonous plants, these being chiefly such as grow 

 in watery places, and many esculent and aromatic ones often 

 yielding gum-resins. The fruit of this Family is never in- 

 jurious : those of Coriander, Anise and Dill, being agreeable 

 aromatics. 



A. Umbels perfect,. Carpels with many ridges , namely, 5 pri- 

 mary, and 4 secondary ones. 



(I. DAUCUS TRIBE.) 



1. DAUCUS. Linn. Carrot. 



Calyx of 5 teeth. Petals obcordatc, point inflexed ; the outer 



