426 swingle: new genus pleiospermii \m 



BOTANY. — Pleiospermium, a new genus related to Citrus, from 

 India, Ceylon and Java. Walter T. Swingle, Bureau 

 of Plant Industry. 



In 1834 Wight and Arnott described 1 as a new species Limonia 

 alata, putting it with Limonia missionis in a section Limoniae 

 spuriae, in contrast to Limonia acidissima, which constituted 

 a section Limoniae verae. All subsequent authors have retained 

 it in the genus Limonia. 



It has been shown 2 that the name Limonia is untenable, so 

 it becomes necessary to find another name for L. alata. The 

 Limonia acidissima of writers on Indian botany is the type of 

 the genus Hesperethusa, the oldest valid name being H . crenu- 

 lata (Roxb.) Roem.; but a comparison of these two plants, 

 both formerly put in the genus Limonia, has convinced the 

 writer that they are not congeneric. The genus Hesperethusa 

 has minute black fruits, usually 4-celled, with only a single 

 seed in each cell; the leaves are pinnate, with a broadly alate 

 rachis; the margins of the leaflets and of the wings of the rachis 

 are crenate. The plant in question, Limonia alata, has fruits 

 about an inch in diameter, usually with two seeds in each cell, 

 the seeds surrounded by a glutinous fluid. The leaves are usually 

 trifoliolate and the leaflets are entire. 



These differences are of much taxonomic significance in this 

 group of plants and in consequence it seems necessary to create 

 a new genus to include Limonia alata and its little-known con- 

 gener, L. dubia Blume. 



In 1896 Engler created under the genus Limonia a new section, 

 Pleiospermium, 3 with a single species, Limonia alata. This 

 being the oldest name for the group, it may be retained as the 

 generic designation. 4 



1 Wight & Arnott. Prodr., 1: 92. 1834. 



2 Swingle, Walter T. The name of the wood-apple, Feronia Limonia. Journ. 

 Wash. Acad. Sci., 4: 325-328. 1914. 



3 Engler & Prantl. Nat. Pflanzenfam., 3 4 : 189. 1896. 



4 Pleiospermium Swingle, gen. nov. (Limonia §Pleiospermium Engl.). Genus 

 Pamburo affine, foliis 3-foliolatis (vel 1-2-foliolatis), tsnuibus, venis conspicuis, 

 disco parvo, parietibus ovarii vesiculis brevibus instructis. 



Folia 3-foliolata vel 2-foliolata vel 1-foliolata, pi'tiolis plus minusve alatis, 



