PITTIER — PLANTS FKOM COLOMBIA AND CENTRAL AMERICA. 95 



two questioned species, I should he willing to abide by Mr. Hems- 

 ley's opinion in this particular and to consider S. duodenum a 

 synonym of S. pleiostackys, but for the following considerations. 

 In the first species the leaves are proportionately' shorter and 

 broader; the primary veins arc more distant and the venation in 

 general is more conspicuous on the lower face of the blades; the 

 petiolar glands are almost always undeveloped; the petioles are 

 broad with their margins turned up so as to form a deep channel on 

 the upper side of the same, while in S. pleiostackys they are scarcely 

 sulcate, a differential character that escaped my notice at first. 

 Furthermore, after a new T and careful investigation of the flowers, I 

 have to confirm every detail in the descriptions given, and it will not 

 weaken the case to add that while the last-named form grows 

 almost at sea level on the semiarid coast of the Pacific, S. anadenum 

 is a mountain tree, the specimens of which were collected in the 

 damp forests (Regenwalder) of the Reventazon basin. 



In a letter dated March 5, 1910, Mr. Hemsley says in part: 

 Mr. Tonduz has sent to Kew a small piece of " Sapium anadenum^ and I now think 

 it may he specifically distinct from $. jama :i 'cense, but the material is insufficient for 

 me to form a definite opinion. 



I am confident that a further examination of complete specimens, 

 which are unfortunately not available at present, would not only 

 dispel all doubt of the specific value of S. anadenum, but would also 

 satisfy as to the distinctive merits of S. pleiostackys. The difference 

 between S. jamaicense and S. pleiostackys can be seen at a glance, 

 even by one who is not an expert in descriptive botany. 8. pleiosta- 

 ckys has very slender petioles and small, shiny leaf blades, and the 

 midrib forms on the upper face a linear furrow (instead of a broad 

 one as in the West Indian species). Setting aside the Guatemalan 

 specimen, we find that the margin of the leaves is always entire or at 

 the most obscurely sinuate; the primary veins are closer, more 

 numerous, and less apparent. The floral spikes are mostly in clus- 

 ters of 4, and there are from to S flowers (and not 3) with each 

 bract. As stated above, the description of the capsules should be 

 eliminated, since the ones at hand were those of Donnell Smith no. 

 2607, wrongly included in the species by myself. 



Only the following changes, then, need to be introduced into the 

 nomenclature of Sapium within the scope of my former paper: 



Sapium jamaicense Sw. Adnot. Hot. 62. 1S29. 



Donnell Smith no. 2607. Capsules and leaves only. 



Sapium ruizii Ilemsl. Hook. Icon. pi. 2894. 1909. 

 Mexico or Central America (Ruiz & Pavon). 



Sapium simile Ilemsl. loc. cit. (text). 



Central America (Ruiz & Pavon). 

 Sapium macrocarpum Mueller Arg. Linnaea 32: 1 19. 1863. 



5. mexicanum Hemsl. Hook. Icon. pi. 2680. 1901. 



