THE TLOEA OF THE NORTHERN TERRITORY. 271 



Flower-beads on separate peduncles. 



Involucre ovoid, without leafy bracts. Pappus of capillary bristles 



witb a few or a ring of short ones outside. — 1. Vernonia. 

 Involucre ovoid, consisting of few herbaceous bracts. Anthers 

 almost tailed. Pappus of 2 to 4 exceedingly deciduous short 

 bristles. — 1. Pleuroearpsea. 

 Flower-heads small, sessile, in a cluster or compound head. 



Involucres narrow, flattened. Pappus of a few rigid bristles. — 3. 

 Elephantopus. 

 Tribe II. Asttroidea.. — Leaves alternate or very rarely opposite. Flower- 

 heads either heterogamous or dioecious, the female florets ligulate or filiform, 

 the hermaphrodites or males tubular and 4- or 5-toothed, or (in very few excep- 

 tional species) the florets aU hermaphrodite and tubular. Anthers various. 

 Style-branches in the hermaphrodite florets usually more or less flattened, 

 produced beyond the stigmatic lines into tips or appendages, papillose on the 

 outside. 



Female florets hgulate, formiag a ray to the flower-head. 



Pappus of the ray or of all the florets of capillary simple or plumose 

 bristles. 



Achenes terete or sUghtly flattened. Ray-florets in a single row. 

 Anthers obtuse at the base or shortly pointed. Involucral 



bracts with dry scarious margins. — 8. Olearia. 

 Anthers with flne tails. Involucral bracts drj^ or the 

 outer ones leaf -like. Ray -florets often irregular. — 11. 

 Pterigeron. 

 Achenes much flattened. Ray-florets numerous, usually in 

 several rows. 

 Achenes all fertile, produced into a slender beak bearing a 



capillary pappus. — 7. Podocoma. 

 Achenes all fertile, not beaked, the capiUarj' pappus sessile. — 



6. Vittadinia. 

 Achenes of the ray fertile, with a capillary pappus, those of 

 the disk mostly abortive, ^^ith a reduced or scaly 

 pappus. — 4. Minuria. 

 Pappus of rigid, unequal, usually divaricate awns or spines, some- 

 times accompanied by scales. — 5. Calotis. 

 Female florets fibform or irregular. 



Flower-heads small, closely sessile, in dense clusters or compound heads. 

 Involucral bracts linear, herbaceous or scarious. 



Pappus none. Anthers mthout tails or points at the base. — 



15. Sphseranthus. 

 Pappus of capiUary bristles. Anthers with short tails or 

 points at the base. — 16. Pterocaulon. 

 Involucral bracts dry, rigid and acute. Anthers tailed. Pappus 

 of a few rigid bristles, flat and scale-like at the base. — 12. 

 Thespidium. 

 Flower-heads separately pedunculate or rarely sessile, but distinct. 

 (A few species of Olearia have the ray-florets minutely and im- 

 perfectly hgulate.) 

 Pappus of simple capillary bristles. 



Involucral bracts narrow-linear, herbaceous or soft. Style 



of the disk-florets branched. — 9. Blumea. 

 Involucral bracts rigid, often broad. Some or all the disk- 

 florets sterile, with a simple style. — 10. Pluchea. 



