1960] 



SPATHIPHYLLUM 



3 



45 



J30 



L5 







_30 



J5 



45 



Fig. 1. Geographic distribution of Spathiphyllum. Numerals indicate the number of species 

 in each area. Note the presence of a single species (S. laeve) on Cocos Island, and another 

 (S. commutatum) in the Indonesian-Philippine area. 



and Orontieae. This treatment appears to be completely natural, and suggests 

 that of Schott (Gen. Aroid. 1858), who placed Spathiphyllum between 

 Anthurium and Orontium. 



Spathiphyllum is often confused with Stenospermatium and Rhadospatha. 

 The latter two genera differ from Spathiphyllum in having flowers without 

 perianth, a somewhat convolute spathe deciduous at anthesis, and a stem with 

 elongate internodes. 



The sections of Spathiphyllum are differentiated by (1) the discreteness or 

 union of the perianth segments, (2) the form of the style and its length in 

 relation to the perianth, and (3) the manner of attachment of the spathe upon the 

 peduncle. Species differences are much less outstanding. The variation and the 

 relative taxonomic merit of each structure are discussed below. 



Leaf -blade. The length/width ratio of the blade is a constant feature useful 

 in differentiation of many species of Spathiphyllum , while the absolute size of 

 the blade varies greatly. Shape of the blade is an important species characteristic, 

 but the point at which the blade is widest varies somewhat. Texture of the blade 

 is difficult to evaluate, especially in specimens glued firmly to an herbarium sheet, 

 and is rarely considered in separating species. 



The base 5 of the leaf -blade may be acute or obtuse to subrotund, and is 

 relatively constant within a species. It is noteworthy that the broad leaf-base 



5 The "base" of the leaf -blade here indicates the lower one-third or one-fourth of the 

 blade where the leaf -margins converge toward the midrib; it should not be confused witli the 

 ultimate narrowing of the blade in some species into a small deltoid process. 



MORPHOLOGY 



