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MEMOIRS OF THE NEW YOKE BOTANICAL GARDEN 



[VOL. 10 



ever, modified in accordance with the narrow, in some species needle-like, shape. 

 In each of the three species studied, a prominent extension is present on the 

 bundle sheath of the midvein, although lateral veins lack them. Little differen- 

 tiation into palisade and spongy parenchyma can be discerned, except in I), 

 rubiceps (fig". 27), where two layers of palisade and seven of spongy tissue may 

 be recognized. Thick cuticle is present on both surfaces of the leaves of all spe- 

 cies. Stomata in Duidaea leaves are confined to the lower surface on either side 



Figs. 25-29. Transections of leaves, adaxial face above. Fig. 25. Duidaea tatei, Steyer- 

 marlc 58204; diagram (symbols explained in text). Fig. 26. D. pinifolia, SteyermarTc 58143; 

 transection entire leaf. Fig. 27. T). rubriceps, Tate 1042 ; portion of transection including mid- 

 vein. Fig. 28. Anastraphia cowellii, Howard 5098 (A) ; portion of transection. Fig. 29. Stiff- 

 tia chrysantha, Trinidad Bot. Gard. 1330. (GH) ; portion of transection. 



