876 PATAGONIAN EXPEDITIONS I BOTANY. 



3. Panargyrus. Heads in terminal glomerules. Pappus-setae numerous, 



i-2-seriate, not easily deciduous, sometimes plumose. 



4. Ma stigop horns. Heads solitary. Pappus-scales numerous, 1-2- 



seriate, or few. 



KEY TO THE SPECIES. 

 A. Heads in terminal glomerules. 



b. Nasscea. Pappus pales 3-5, deciduous. Shrubs with ovate leaves. 



c. Leaves dimorphous, spiniferous, entire on sterile shoots, pinnatifid on floral stems. 



heterophylla. 



c2. Leaves imbricate, spinose-toothed. Low, branching, glabrous. nordenskjoldii. 



^3. Leaves glabrous, rigid, imbricate, black-tipped. Dwarf cespitose. pumila. 

 f4. Leaves revolute, with impressed parallel costae. 

 d. Glomerules subglobose. 



e. Leaves entire, hirsute on lower surface. nivalis. 



c2. Leaves spinulose-serrate, pubescent at first. revoluta. 



d2. Glomerules large, ovate. Leaves serrate, silky. serpens. 



d$. Glomerules in a short spike. Leaves gray-pubescent. dusenii. 



c$. Leaves imbricate, impressed-striate, recurved margin and apex, silvery underneath. 



Glomerules at length leafy. argentea. 



62. Panargyrus. Pappus setae i-2-seriate, often plumose, not deciduous. 

 c. Fruticose. 

 d. Cespitose. 



e. Leaves linear, rigid, entire, glabrous. Pappus plumose. abbreviata. 



C2. Leaves obovate-cuneate, recurved, covering all the stem. 



lagasca (of H. & A.). 

 d2. Stem and leaves silky. Pappus plumose. 



e. Leaves linear-subulate, short. Heads in a terminal golden mass. 



candollei. 

 e2. Leaves linear, subulate, pungent. Flowering branches scape-like. 



darwinii. 

 ^3. Leaves sparse, linear, entire, soft, obtuse. Heads crowded apically on the 



branches. laxa. 



d~$. Hoary velvety. Ascending. Leaves crowded at base, pinnatifid, spinose. Ter- 

 minal racemes on branches. spinosa. 

 C2. Herbs, with spinose leaves. 



d. Erect, simple stem. Leaves villous, cuneate, ovate, incised. suaveolcns. 



d2. Subcespitose. Leaves glabrous to webby, linear-lanceolate. Pappus not plu- 

 mose, subspinosa. 

 A2. Strongyloma. Heads in axillary glomerules, forming a leafy spike. 



b. Leaves oval, toothed-ciliate at base, apically recurved. Cespitose shrub. Pappus pales 3-4. 



pygmcea. 



b2. Primary leaves subtending secondary fascicles. 

 c. Primaries subulate, sheathing. 



d. Secondaries linear-mucronate, recurved. Heads subternate. axillaris. 



d2. Secondaries complicate-incurved. Heads solitary. glomerulosa. 



