802 PATAGONIAN EXPEDITIONS I BOTANY. 



&2. Branchlets sulcate. 



c. Dwarf. Leaves small, linear, subentire. Heads solitary on the branches. 



nana. 



c2. Leaves lance-linear, pectinately spinulose. Heads subcorymbose. melanopotamica. 

 b^. Branches striate. Glabrous. 



c. Leaves few, sessile, linear, entire. Heads 35 on the branches. genistifolia. 



c2. Leaves pinnatifid, decurrent, segments narrow, mucronulate. Heads corymbed. 



pinnatifida. 

 c$. Leaves subulate, mucronate, often pinnatifid. Heads solitary on ends of branches, 



often corymbed. ulicina. 



A^.. Various. 



b. Tall shrubs with spongy wood, and lance-linear, resinous leaves. Corymbs, salicifolia. 



b2. Erect shrubs, with firm stem, ovate-lanceolate, serrulate leaves, subglabrous. Heads 



corymbed. serrulata. 



b-),. Subglaucous herb, with rush-like stems, and linear, distant leaves. juncea. 



4. Low, branching shrub, leafy above, scars below. Leaves oblong, toothed-setose. Male 



heads small, solitary. . dusenii. 



b$. Branches punctulate, laxly leafy. Leaves narrow, punctulate. Corymbed. pingrcea. 

 66. Branchlets and leaves resinous-glandular. Leaves linear, obtuse, thickish. Corymbed. 



rosmarinifolia. 

 b"j. Branches crowded, erect. Leaves small, crowded, hoary underneath. Heads solitary, 



terminal. bryoides. 



68. Glabrous, branching annual. Leaves linear-subulate. Heads subcorymbose. 



snbulata. 



bg. Inflorescence paniculate. Involucre woolly, lax. artemisioides. 



b\o. Inflorescence umbelliform. Leaves obovate-cuneate, toothed. lunbelliformis. 



b\\. Imperfectly known. 



c. Heads subsessile, spicate, leafy, terminating the branches. rufescens. 



c2. Leaves opposite, lanceolate. iirvilleana. 



i. BACCHARIS ARTEMISIOIDES Hook. & Arn. 



Habit of Artemisia absinthium, from a racemiform panicle and woolly 

 involucre. Involucral scales lax, rather broad. Heads androgynous, 4 

 mm. diam. 



Argentina; N. Patagon., by Rio Negro. 



2. B. BRYOIDES PerS. 



Branching, prostrate undershrub ; with crowded, erect branchlets. 

 Leaves very small, crowded, linear, hoary beneath. Heads 6-8-flowered, 

 terminal, solitary, sessile. Involucre cylindrical, its scales oblong. 



"Magellan Strait or Patagom'an shore" (Commerson). "Genus doubt- 

 ful" (DC. Prodr.). 



