120 PROCEEDINGS OP THE AMERICAN ACADEMY. 



1 to 2 dm. long, 2 to 8 cm. broad, acumiuate, acute, serrulate, narrowed 

 at the base into a 3 to 5 mm. long petiole, dark green and glabrous 

 above, arachnoid- tomentulose beneath, jjellucid-punctate, subparallel 

 5-nerved ; midrib and the two pairs of lateral nerves prominent on the 

 under side of the leaf-blade : heads of pistillate flowers large, 4 to 5 cm. 

 high, 5 to 7 cm. broad, terminating the stem and branches on short 

 stout peduncles : involucre about 8-seriate, arachnoid-tomentose ; scales 

 of the involucre lance-acuminate, appressed or slightly squarrose, the 

 outer successively shorter : rays about 1 cm. long, 2 mm. broad : disk- 

 flowers numerous ; pappus of many slender setiE : heads of staminate 

 flowers about 2 cm. high and broad, on short peduncles : involucre 

 4— 5-seriate, arachnoid-tomentose ; scales of the involucre lance-oblong, 

 obtuse, appressed or very slightly spreading, the outer shorter than the 

 inner ; rays narrowly oblong, 10 to 12 mm. long, 3 mm. broad. — Costa 

 Rica, Forets des collines de Nicoya, February, 1900, Ad. Tonduz,uo. 

 13,602 (hb. Gr., and hb. Inst. Phys.-Geog. Cost. Ri.), pistillate plant ; 

 boussailles a Nicoya, January, 1900, Ad. Tonduz, no. 13,620 (hb. Gr., 

 and hb. Inst. Phys.-Geog. Cost. Ri.), staminate plant. 



Notwithstanding the considerable difference in the size of the heads 

 of the two specimens above cited, the writer has no doubt that they 

 represent the pistillate and staminate plants of one species. In the stem 

 and foliar characters there is absolute identity. 



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