1877.] Knowledge of tliG Burmese Flora. 1G3 



Trih. I. Corymliferce, Vaill. Florets all tubular, or more usually the 

 marginal ones ligulate and forming a ray. Style not thickened joint-like 

 at or near the apex. Herbs, shrubs, or trees, usually aromatic. 



* Flower-heads hcterogamous, radiate or discoid^ the hermaphro- 

 dite or male florets tuhular, and the female ones ligulate or 

 filiform {or rarely the heads homogamous in absence of the 

 ray -florets) . 



+ Anthers free or nearly so. Female flowers all apetalous. 

 Flower-heads unisexual, rarely heterogamous. 

 Suhtrih. 1. AMBROSIE^. Style of hermaphrodite florets* undivided. Anthers 

 inflexed-appendaged. Pappus none. Leaves alternate. 



Xanthium. Male florets numerous, in globular heads, the involucre small, consis- 

 ting of free bracts in a single row. Female florets 2 together cousolidated with the 

 involucre into a prickly burr. 



-f -f Anthers always united into a tube. Style-branches 

 truncate or appendaged. 

 X Pappus of short stiff awns or scales, or reduced to a 

 raised border, or none at all. (Genera with a simi- 

 lar or no pappus, not included here, should he sought 

 for in the next division with capillary bristles). 

 Anther-cells not tailed at the base. 

 Suhtrih. 2. EELIANTHOILEvE. Flowers either heterogamous, with the female 

 florets more or less ligulate, the central ones tubular hermaphrodite or male, or rarely 

 discoid, with all the florets hermaphrodite and tubular. Eeceptacles with chafi"y scales 

 between the florets, or rarely (in Helenioidece) naked. Anthers without tails. Style 

 branches truncate and penicillate, or appendiculate, or the style of the sterile flowers 

 undivided. Pappus of stiff awns or of short scales or none. Achenes 3 — 4-gonous, 

 terete, or more usually variously compressed. Leaves opposite or rarely alternate. 

 * Receptacle paleaceous (Helianthoidese) . 



+ Pappus consisting of numerous scales, rarely awn-shaped (or none). 

 {^Galinsogece). 

 Galinsoga. Flower-heads radiate, Involucral bracts in 1 or 2 series, almost 

 equal. Scales of pappus oblong, chafi'y, fringed, or the alternate ones, or all, shortly 

 awned. Herbs, leaves opposite. Receptacle conical. 



Tridax. Flower-heads radiate. Involucral bracts in 2 rows, membranous, or the 

 outer ones herbaceous. Scales of pappus feathery-fringed. Herbs, leaves opposite. 

 Receptacle flat or rearly so. 



+ -f ♦ Pappus consisting of only 1 — 4 bristly awns, or cyathiform, or 

 absent. 



X Corolla of the fertile florets persistent on the achenes. Pappus 

 of 1 — 3 awns {Zinniece). 

 Zinnia. Receptacle conical or cylindrical. Disk-florets fertile. Achenes (at least 

 the inner ones) 1 — 3-aristate. Herbs, leaves opposite. Flower-heads solitary. 

 X X Corolla of all the flowers deciduous. 



t Achenes more or less compressed from the top. Pappus of 2 

 (rarely 4) bristles, or none. {Coreopsiclece). 



