240 THE COMPOSITE FAMILY. [Achillea. 



2. A. Millefolium, Linn. (fig. 533). Milfoil or Yarrow.— Stock 

 perennial, creeping undergound, with numerous short, leafy barren 

 branches, and erect, almost simple flowering stems, about a foot high. 

 Leaves oblong, or linear in their outline, but finely cut into numerous 

 short, but very narrow and deeply pinnatifid segments. Flower-heads 

 numerous, small, ovoid, in a dense terminal corymb. Florets of the 

 ray seldom above 5 or 6 in each head, white or pink. 



In pastures, meadows, waste places, &c, very abundant in Europe 

 and Russian Asia from the Mediterranean to the Arctic Circle, and 

 extends over a great part of North America. It is also one of the 

 commonest of British plants. Fl. the whole summer. It varies with the 

 foliage nearly glabrous, or densely covered with white woolly hairs. 



XVI. DIOTIS. DIOTIS. 



A single, very cottony species, distinguished from Achillea by the 

 florets, all tubular, with two projecting ears at the base of the corolla, 

 which enclose the achene and remain upon it after the upper part 

 falls off. 



1. D. maritima, Cass. (fig. 534). 8. Cotton Weed. — Rootstock per- 

 ennial and creeping ; the stems branching at the base, hard and almost 

 woody, seldom a foot high, covered, as well as the leaves and involucres, 

 with a dense, white, cottony wool. Leaves alternate, oblong, entire or 

 slightly toothed, about half an inch long. Flower-heads nearly globular, 

 about 4 lines diameter, in dense terminal corymbs. Florets yellow and 

 small. Receptacle convex with scales between the florets. Achenes 

 without pappus or border except the persistent base of the floret. 



In maritime sands on the Mediterranean and Atlantic. Extends on 

 the English coasts up to Anglesea on one side and Suffolk on the other ; 

 it is found also on the south coasts of Ireland, and the Channel Islands. 

 Fl. end of summer or autumn. 



XVII. TANACETUM. TANSY. 



Herbs, with much divided, alternate leaves. Flower-heads hemi- 

 spherical, in terminal corymbs. Involucral bracts imbricated, scarious 

 at the edges. Receptacle without scales. Florets yellow, all tubular, 

 or the outer ones ligulate but not longer than the others. Achenes 

 angular, with a flat top, without any pappus. 



A small genus from the Mediterranean and Caucasian regions, differ- 

 ing from Artemisia technically in the shape of the achene, but more 

 evidently in the larger, more yellow, corymbose, not paniculate, flower- 

 heads. 



1. T. vulgare, Linn. (fig. 535). Common T. — A stout, erect per- 

 ennial, 2 to 3 feet high, glabrous or slightly downy, with a strong scent 

 and bitter savour. Rootstock creeping. Leaves rather large, pinnate, 

 with oblong-linear, pinnatifid or toothed segments. Flower-heads 

 numerous, hemispherical, about 4 lines diameter, of a golden yellow, 

 in a large terminal corymb. 



On the edges of fields, roadsides, and waste places, in Europe and 

 Russian Asia, from the Mediterranean to the Arctic Circle. Extends 

 ail over Britain, perhaps always where introduced. Fl. end of summer. 



