SUNFLOWER FAMILY. 431 



Rich soil of fields: Sacramento Valley; San Francisco and southward to 

 Southern California. 



32. TANACETUM L. 



Strong-scented perennial herbs. Leaves 2 or 3 times pinnately divided into 

 numerous small lobes. Heads discoid, many-flowered, borne in a corymb-like 

 peduncled cluster. Flowers yellow. Involucre of numerous scale-like bracts. 

 Receptacle flat or low, naked. Achenes 5-ribbed or 3 to 5-angular, with broad 

 truncate summit bearing a low crown-like pappus or none. (Name obscure.) 



1. T. camphoratum Less. Dune Tansy. Villous-tomentose when young, 

 the wool more or less deciduous in age; herbage with the aroma of camphor; 

 stems robust, decumbent or ascending, 1 to 2% ft. long; primary and sec- 

 ondary divisions of leaves much crowded, the latter oval or oblong, the mar- 

 gin more or less revolute; achenes glandular. 



Sand-dunes at San Francisco. Aug.-Xov. 



33. ARTEMISIA L. Sage Brush. 

 Herbs or shrubby plants, mostly bitter and aromatic, with alternate leaves. 

 Heads small, nodding or erect, in panicled spikes or racemes. Flowers yellow 

 or purplish ; rays none. Disk-flowers perfect and marginal ones pistillate or all 

 perfect. Rays none. Corollas of the pistillate flowers 2 or 3-toothed, of the 

 perfect flowers 5-toothed. Involucre imbricated, dry and scarious. Receptacle 

 nearly flat, naked. Achenes obovoid or oblong, glabrous, with a small terminal 

 areola. Pappus none. (Xamed for Artemisia, wife of Mausolus, king of Caria.) 



Shrub; herbage grayish-puberulent; leaves linear-filiform and entire or with linear filiform 



divisions; involucre hemispherical 3. A. californica. 



Herbaceous or somewhat woody at base. 



Involucre oblong; leaves green above, commonly white-tomentose beneath, broad, often 



pinnatifid I. A. heterophylla. 



Involucre hemispherical. 



Herbage green, glabrous; leaves bipinnately divided, the divisions serrulate or incised.. 



2. A. biennis. 



Herbage green and nearly glabrous; leaves linear, entire 4. A. dracunculoid.es. 



Herbage densely silky-villous all over; leaves once to thrice pinnately divided into 

 linear entire segments 5. A. pycnocephala. 



1. A. heterophylla Nutt. California Mugwort. Stems from running 

 rootstocks, erect, woody at base, strict, 3 to 6 ft. high; leaves lanceolate to 

 oblong, ovate or elliptic, sparingly pinnatifid (with downward incisions), cleft 

 or often entire (especially the upper), green above, white-tomentose beneath, 

 sometimes glabrous; heads mostly erect, in dense spikes in an open or more 

 commonly dense terminal panicle, the main axis leafy; involucre oblong, 

 glabrous; marginal flowers pistillate, disk-flowers perfect, all fertile, as also 

 in the next two species. 



Common along stream-banks and elsewhere throughout California. Leaves 

 usually large, often 6 in. long and 2% broad, exceedingly polymorphic as to 

 the margin. 



2. A. biennis Willd. Glabrous inodorous tastless biennial, erect, virgate, 

 l l j to 3 ft. high; leaves bipinnately divided into lanceolate or broadly linear 



oi serrulate divisions, or the uppermost merely pinnatifid; heads 

 crowded on the short branchlets, the whole inflorescence spike-like and more 

 or Less Leafy; achenes with small epigynous disk. 



Introduced weed: West Berkeley; lower Sacramento River. 



3. A. californica Less. Old Man. Gray shrub, 2% to 4 ft. high; leaves 

 with a minutely cippressed pubescence, the lowest palmately once or twice 

 parted into linear-filiform segments, the upper entire and more or less fas- 



