xm, c, 6 Swingle: Merillm, a new Rutaceous Genus 337 



Museum, at South Kensington, in 1911, I now feel able to discuss 

 this remarkable species, in many ways unique among- the plants 

 closely related to Citrus. In the first place all the known mem- 

 bers of the tribe Citreae have either unifoliolate leaves or else 

 pinnate leaves with strictly opposite leaflets. The other genera 

 of the subfamily Citratae, such as Chalcas (Murray a) , Clausena, 

 Glycosmis, and Micromelum, have pinnate leaves with alternately 

 arranged leaflets but never with a winged rachis. Up to now 

 a single leaf, even if immature, would serve to distinguish 

 any of these genera from the true Citreae. The Singapore 

 plant has pinnate leaves with alternate leaflets and a narrowly 

 but clearly winged rachis. All the pinnate-leaved members of 

 the subfamily Citratae have a clearly marked petiole below the 

 first pair of leaflets. The flowering specimen of Murraya cal- 

 oxylon, collected in the Singapore Botanic Gardens in March, 

 1918, shows sessile or subsessile leaves, the lowest leaflets being 

 very small, nearly opposite, and attached near to or at the very 

 base of the rachis. The fruits are even more remarkable, being 

 like Chaetospermum in having a leathery rind, but differing 

 widely in the irregularly lacunose pericarp and in having the 

 walls of the locules solid. The seeds at first glance seem to 

 be hairy like those of Chaetospermum and Aegle, but closer 

 examination of what appear to be hairs shows that they are 

 thin, elongated, somewhat fimbriate paleae. The seeds also show 

 an ariloid ridge at one edge, unlike the seeds of the other mem- 

 bers of this subtribe. 



Many other characters of less importance serve to mark off 

 this plant as perhaps the most remarkably aberrant of the 

 citrous fruits. 



I take pleasure in naming this remarkable new genus in 

 honor of Professor E. D. Merrill, who has done so much valu- 

 able work on the flora of the Philippines, the Malayan region, 

 and southern China. 



MERRILLIA genus novum 

 (Rutaceae, Citratae, Balsamocitrinae) 



Genus Chaetospermo (Roem.) Swingle ut videtur affinis 

 perspicue differt ovario 5- vel 6-loculare, pericarpio irregulariter 

 lacunoso, seminibus dense paleaceis, paleae elongatae, membra- 

 naceae, leviter laciniatae, foliis sessilibus, pinnatis, rhachibus 

 anguste alatis, foliolis alternis. 



Arbor inermis. Folia pinnata, sessilis vel subsessilis, rhachi- 

 bus anguste alatis; foliola alterna, inferioribus parvis, sursum 

 gradatim majores, terminalibus majoribus; petiolulo brevissimo. 



