436 coMPosiTJE. (composite familt.) 



in 2-3 rows. Receptacle chaffy. Anthers caudate at base. Akenes 

 very small, prismatic, crowned with a short, 1-rowed, haii'-like pappus. 

 Perennial herbs, Avith wand-like, erect stems. 



Ch. iiioiitanuni, DC. If .3 to .4, appressed-silvery-canescent, 

 woody at base, many-stemmed. Leaves entire, the lower tapering to a 

 petiole, the upper oblong-lanceolate, sessile. Heads .01 in diameter, 

 peduncled, subtended by 3-3, lanceolate braets as long as or longer 

 than the involucre ; scales of involucre linear-lanceolate — June and 

 July — Rocks ; Aintab, and northward. 



25. POSTIA, Boiss. et Bl. Postia. 



Heads many-flowered, radiate or discoid. Involucre imbricated 

 in about 2 rows. Receptacle chaffy. Marginal flowerets pistillate, either 

 strap-shaped, 3-toothed, in one row, or filiform, very few. Anthers short- 

 caudate. Akenes somewhat flattened, 4-angled, hirsute, uniform. 

 Pappus double, the outer of very short, persistent hairs, the inner of 

 2-3, elongated, barbellate pales, dropping early — Woolly herbs, with 

 many stems from a woody root-stock. 



1. P. lanuginosa, DC. .3 to .8, pannous-canescent ; stems 

 numerous, wand-like, rigid, 1-3-headed. Lower leaves obovate-spathu- 

 late, tapering to a petiole, upper sessile, lanceolate, .025 long, entire or 

 denticulate, bearing buds in axils. Heads .02 'broad, rayed; outer 

 scales of involucre lanceolate, rather obtuse, inner lanceolate-linear ; 

 rays twice as long as involucre ; inner pappus of 2 pales, that of rays 

 oftener of 1 — June and July — Rocky hillsides ; Wadi Ibrisah (Le- 

 banon) ; northern Coelesyria and Antilebanon to Damascus, and 

 Palmyi-ene desert. 



2. P. microcepbala, Boiss. 5 -25, pannous-canescent ; stems 

 wand-like, rigid, 1-headed. Leaves oblong-spathulate, .012 long, 

 rather obtuse, tapering at base. Heads smaller tJiaa a pea, discoid ; 

 scales of involucre somewhat concealed in wool, oblong ; pistillate 

 flowers very few ; inner pappus of three pales — Summer — Plain of 

 Ma'liilah (Antilebanon). 



26. AI9IBROSIA, Tourn. Ragweed. Ambrosia. ^Anbariyeh. 



Monoecious. Staminate heads, hemispherical ; scales of involucre 

 united in a cup ; flowerets tubular, 5-toothed ; receptacle bristly ; 

 anthers free. Pistillate heads 1-flowered, enclosed each in an ovate, 

 bladdery involucre, closed except at tip, indurated in fruit, and taper- 

 ing into a beak enclosing the style. Heads clustered, surrounded by 

 bracts. Stigmas 2, filiform, protruding. Akenes bald — Annual herbs, 

 lower leaves opposite, upper alternate. Spikes terminal, bearing pistil- 

 late heads at base, frequently compound, and staminate heads toward 

 tip. 



A. maritiina, L. © ''Useirah. Ghubeirah. JDemsts. .5 to .8, 

 appressed-canescent. Leaves ovate in outline, 2-pinnatipartite into 

 toothed, oblong lobes. Involucre of pistillate flowerets surrounded 

 about the middle with 4-6, blunt, horn- like projections — January to 

 October — Coast. 



