Matricaria. COMPOSITE. 363 



A. n6bilis, L., the officinal Chamomile, a low perennial, with pleasant aiomatic filiform]/ 

 dissected foliage, not uncommon in gardens, is said to be occasionally spontaneous, but rarely. 



A. TiNCT6RrA, L., — an erect herb, rather stout, with large heads, yellow rays, or occasionally 

 pale or partly white, and quadrangular akenes, — has sometimes escaped from gardens. 



1 72. ACHILLEA, Vaill. Yarrow. (After Achilles.) — Perennial herbs ; 

 with small and corymbosely cymose heads of white, yellow, or sometimes rose- 

 colored flowers, at least in the ray ; disk commonly yellow. — Linn. Gen. no. 661. 

 Ptarmica & Millefolium, Tourn. Ptarmica & Achillea, DC. — Many Old-World 

 species, very few American, all perennial. 



§ 1. Heads rather narrow: receptacle at length elevated. — Achillea, DC. 



A. Millefolium, L. (Milfoil or Yarrow.) From villous-lanate to glabrate: stems 

 simple, a foot or two (on high mountains a span) high : leaves elongated and narrow in out- 

 line, sessile, bipinnately dissected into numerous small and linear to setaceous-subulate divis- 

 ions : heads numerous, crowded in a fastigiate cyme : involucre oblong ; its bracts pale or 

 sometimes fuscous-margined, or even wholly brownish : rays 4 or 5, about the length of the 

 involucre, white occasionally rose-color. — Very variable ; in grassy fields of Atlantic States 

 green and more or less glabrate, and with open foliage (perhaps introduced from Europe) ; 

 northward and on mountains mostly lanate (var. lanata, Koch), with divisions of the narrow 

 leaves much crowded; including A. gracilis & A. occidentalis,Jla,i. in DC. Prodr. vi. 24; 

 A. tomentosa, Pursh, Fl. ii. 319. A. lunulosa, Nutt. Jour. Acad. Philad. vii. 36; A. setacea, 

 Schwein. in Long Exped. ii. 119. Form with dark involucre, A. Millefolium, var. nigrescens, 

 E. Meyer, PI. Labrad. ; A. borealis, Bong. Veg. Sitch. 149. Ptarmica borealis, DC. — Com- 

 mon from Labrador to Alaska, south to Texas and California. (All N. hemisphere.) 



§ 2. Heads broader : involucre campanulate : receptacle low. — Ptarmica, 

 Tourn., DC. 



A. multifiora, Hook. Villous-pubescent, soon glabrate : stem strict, 2 feet high : leaves 

 linear, closely pectinate-pinnatifid into lanceolate-subulate minutely denticulate lobes, the 

 sinuses extending fully half-way to the midrib : heads in rather a close cyme : rays 10 or 12, 

 very short and small, white. — Fl. i. 318; Torr. & Gray, Fl. ii. 409. A. Ptarmica, Richards, 

 in Frankl. Journ. 33. — Saskatchewan to Fort Franklin and Behring Strait ; first coll. by 

 Richardson and Drummond. 



A. Ptarmica, L. (Ssjeezewort.) A foot or two high, loosely branching above, bearing 

 more loosely disposed and pedunculate heads : leaves glabrous, linear, finely and closely ser- 

 rate: rays 8 to 12, comparatively large, roundish, white. — Fl. Dan. 643 ; Engl. Bot. 757 ; 

 Pursh, Fl. ii. 552. Ptarmica vulgaris, Blackw. Herb, t 256; DC. Prodr. vi. 23. — "Open 

 dry swamps, Canada and New York," Pursh. The latter habitat unsupported. New Bruns- 

 wick, apparently indigenous in Restigouche and Kent Counties, Fowler. Locally naturalized 

 in Mass. and Michigan. (Eu., N. Asia.) 



173. MATRICARIA, Tourn., L. (Name given by the herbalists, from 

 mater or matrix, to herbs of reputed medicinal virtues.) — Herbs, chiefly of 

 Europe and Asia ; with finely once to thrice dissected leaves, and pedunculate 

 heads, the disk-flowers yellow, those of the ray white,-- or occasionally (and in one 

 of our species constantly) wanting. — Benth. & Hook. Gen. ii. 427. 



§ 1. Akenes obpyramidal, with 3 strong and thick (lateral and facial) ribs. — 

 Tripleurospermum, Schultz Bip. Chamcemelum, Visiani ; Boiss., in part. 

 M. inodora, L. Nearly scentless, annual, an arctic form apparently biennial or perennial : 

 leaves 2-3-pinnately divided into filiform or narrow linear lobes : heads large : rays half to 

 three-fourths inch long : receptacle at length ovate : pappus a, minute entire or 4-toothecl 

 border. — Fl. Suec. ed. 2, 297 ; DC. Prodr. vi. 52 ; Torr. & Gray, Fl. ii. 412. Chrysanthemum 

 inodorum, L. Spec. ed. 2, 1253 ; Fl. Dan. t. 696 ; Schk. Handb. t. 253. Pyrethrum inodorum, 

 Smith, Engl. Bot. t. 676 ; Hook. Fl. i. 320. Tripleurospermum inodorum, Schultz Bip. Tana- 



