77 PATAGONIAN EXPEDITIONS: BOTANY. 



* 



d. Head 1-15 -flowered. Achenes long-linear, 8-io-ribbed. 



42. Flavcria, p. 825. 



d2. Head many -flowered. Achenes linear and few-ribbed, prismatic or obpyramidal, 

 triangular, the marginal sometimes winged. Rays ligulate. Involucral scales 

 free. 43. Villanova, p. 825. 



c 2. Pappus of free scales, obtuse or acute or pointed. Involucral scales herbaceous, erect, 

 not enclosing the marginal achenes. Female corollas ligulate or none. Style- 

 branches of hermaphrodite flowers rounded or truncate. Achenes obpyramidal. 



44. Actinella, p. 826. 

 b2. Receptacle convex, with stiff setae between the flowers. Pappus of 5-10 hyaline scales, 



terminating in awns. 45. Gaillardia, p. 826. 



A2. Plants with large oil-glands in the leaves and involucres. Herbs. 



b. Pappus of 3-6 very unequal scales. Heads often discoid. 46. Tagetes, p. 827. 

 b2. Pappus of 10 to many scales, often similar, or partly similar. Heads distinct ; female 

 flowers none or ligulate. 47. Dysodia, p. 828. 



Tribe VII. Antliemidece. (Genera 48-52), p. 828. 



A. Receptacle chaffy. Disk flowers fertile ; achenes not woolly ; corolla not persisting. Style- 

 branches truncate, not appendaged. Herbs, with leaves alternate, often much parted. 

 b. Achenes not or only slightly compressed. Head heterogamous, or homogamous, and 

 then with pappus none or i -sided, like an auricle. Corolla-tube compressed, winged, 

 tubercled or spurred. Heads on terminal peduncles. 48. Anthemis, p. 828. 



b2. Achenes much compressed, not winged. Pappus none. Heads mostly rather small and 



corymbed. 49. Acliillea, p. 829. 



A2. Receptacle without chaff. Heads heterogamous, disciform. Corolla of female flowers 

 tubular or none. Style-branches of hermaphrodite flowers penicillate, even when un- 

 fruitful. 



b. Hermaphrodite flowers 4-merous. Involucre simple, its scales I 2-, rarely 3-seriate, sub- 

 equal. 



c. Head pediceled at end of the branches. 50. Cotula, p. 829. 



c2. Heads solitary, sessile, or in dense corymbs. Female flowers in i series. 



51. Abrotanella, p. 831. 



b2. Hermaphrodite flowers 5-merous. Female flowers in i series. Involucral bracts few- 

 seriate, scarious margined, the outer gradually smaller. Heads small, usually crowded 

 but not corymbed. 52. Artemisia, p. 832. 



Tribe VIII. Senecionecz. (Genera 53-55), p. 832. 



1. Heads with female ray-flowers, whose corollas are tubular, or filiform, or irregularly 4-5- 



lobed. Leaves small, entire, closely compressed. Branches all leafy ; heads sessile in the 

 upper leaves as an extra involucre. Proper involucre i-2-seriate, with black-tipped scales. 

 Achenes glabrous. Low, cespitose herb. 53. Mclalcma, p. 832. 



2. Heads homogamous. Involucre 3-several-seriate. Pappus hairy. Achenes glabrous. Un- 



branched or slightly branched herbs, with radical and alternately cauline leaves. 



54. Culcitium, p. 833. 



