402 r(JMPOSIT,E. Taaacduin. 



93. TANACETUM, Linn. Tansy. 

 Head muiiy-llowered, lieteiogcimous, with the ilovvers all tubular, the uutenuost 

 series pistillate, or rarely these wanting when the flowers are all perfect, mostly all 

 fertile. Involucre of numerous dry more or less scarious and brownish imbricated 

 and appressed scales, lieceptacle flat or convex, naked. Corollas of the pistillate 

 flowere ecjually or obliquely 2 - 5-toothed ; of the perfect flowers 5-toothed. Akenes 

 generally about 5-ribbed or angled, or the marginal ones 3-sided ; the broad trun- 

 cate summit bearing a short and scarious coroniform pappus, or none. — Strong- 

 scented herbs ; with alternate mostly compound or lobed leaves, and corymbose or 

 mrcly solitary erect lu^ads of yellow flowers. 



A mcHlenitcly lurgo gt'Uiis in thu Old World, wiilcly roiireaonted by T. vulgare, Linn., the coni- 

 nion Tunsji, which, so I'ar as wc know, is not at all naturalized m California ; but there is u 

 stouter iniligenous species on the coa.st related to it. Then, in the interior dry region there are 

 three or four peculiar species (section S/j/i(t;ronicria of Nuttall) related to certain others in Asia ; 

 the one found in California much ap[)roachea Artemisia. Ours are perennials. 



^i Pappus tvideal : leaves very much dissected into inuumei-able divisions. 



I. T. Hnronense, Xutt. Soft-hairy, usually mu(;h so when young: stems 

 stout, a foot or twu liigli, very leafy : leaves twice or thrice pinnately dissecte<l ; tlio 

 very small and numerous lobes oblong or linear and much crowded : h(^ads large, 

 half an inch in tliameter, on sUjut i)etluncles : corollas of the pistillate flowers rather 

 conspicuous and somewhat ray-like, 3 - 5-lobed, the tube flattened, slightly winged 

 at base : akenes very obscurely ribbed : pap])us toothed. — T. cainplioratuin, Less. 

 2\ Douglasii, DC. T. elegans, iJecaisne, V\. Serres, t. 1191. Omalanthns campho- 

 ratus, Less. Omalotes caviphorala, DC. 



Sandhills, along the (toast, from San Francisco to Paget Sound. Also on the Ujjpor (Ji'cat 

 liiikos, and from Jludson's May to the iiortlierii borders of Maine. 



* * PdppiiH none: /cares once or twice pinnate! i/ dissected into rather few divisions. 



'2. T. potentilloides, (!ray. Silvery-silky: stems numerous from a stout root, 

 tlilfuse or aseendiiig, a .span to a foot long, spar.sely leafy : radical leaves twice pin- 

 nattdy divided and peticdeil, the cauline mostly sessile and once divided into linear 

 entire lobes ; u])permost reduced to nearly simple bracts : heads 3 to G in a loose 

 corymb (sometimes rathcsr panicled), hemispherical, about 3 lines broad : scales of 

 tiie involucre about 10, broadly obovate, silky-tomentose : receptacle flattish, very 

 hirsute: llowcus all fertile; the pistillate ones with a small and slender 2-3- 

 toothed corolla: akenes obovate-turbinate, 3 - ^-angular, thin and vesicular, with 

 truncate broad summit. — Proc. Am. Acad. ix. 204. Artemisia potentilloides, (hay, 

 Proc. Am. Acad. vi. 55L 



Kastern part of the Sierra Nevaila, in Sierra Valley (Lemmon), and Carson City, Nevada, 

 .Indcrsou. Tlie corymbose heads as well as tlie broad and abru])t top of the akene refer this to 

 Ttinacetum. The akene is thin and utricular, forming a loose investment to the seed : when 

 soaked it swells up and lieeomes jelly-like ; and its cells under the microscope siiow spiral 

 threads. 



94. ARTEMISIA, Linn. Wou.mwoud. Saok-uusu. 

 Head several -niany-llowered, heterogamous, with the flowers all tubidar and the 

 outermost series pistillate, or liomogamous by the absence of these ; the more 

 numerous perfect flowers either fertile or sterile. Scales of the involucre dry and 

 more or less scarious-margined, imbricated in few series, ajipressed. TJeceptacle flat- 

 ■^i.sh, convex, or hemispherical, nak(!d, sometimes hairy. Corollas of the pistillate 

 llowers slemler and small, 2 - 3-tootii('d ; of the perf.-ct flowers enlarged above. 



