g PHILIPPINE AGRICULTURAL REVIEW. 



species as subspecies and varieties. Such a procedure is more 

 likely to result in further confusion than order." 



The species of the genus Citrus that have come under the 

 observation of the writer, with two exceptions, seem naturally 

 to divide themselves into two groups, (1) those with more 

 or less united filaments and hypogeal cotyledons, and (2) those 

 with free filaments, and (in all instances where there has been 

 an opportunity for observations) with supra-terraneous, distinct 

 cotyledons (fig. 1). In so far as these characteristics have 

 been observed in the Philippine citrus fruits, long and broad- 

 winged petioles are a third correlative feature distinguishing 

 group No. 2; C. ichangensis recently described by Swingle 

 from China also possesses this last feature, but has connate 

 filaments. The alsem and alemow seem to be intermediate be- 

 tween these forms, the alsem being most closely related to those 

 in the first division, the filaments being connate, while the 

 cotyledons in some lots that have been propagated appeared 

 above ground. The alemow is most closely related to group 

 No. 2, the filaments being nearly always free. The general 

 character of the talamisan together with the presence of hypo- 

 geal cotyledons tends to the belief that this species has more 

 or less united filaments and thus would belong to the first group. 



All descriptions have been made from living plant material 

 either during tours of collection by the writer, or from plants 

 grown at the Lamao experiment station from material sent to 

 the Bureau of Agriculture from time to time since April, 1911. 

 Also, all the material has been collected from plants growing 

 in the yard of some Filipino and so may lay claim to having 

 been domesticated. While this statement may not be altogether 

 reliable it is interesting to note that in Bohol the Filipinos 

 stated that the following trees grew wild in the forest : Among- 

 pong, amontay, balincolong, biasong, canci, colo-colo, limoncito, 

 limao, lombog, and samuyao. 



While it is believed that the species described in this paper 

 include most of the more distinctive Philippine citrus fruits, and 

 several hitherto unknown even to the botanist, they do not by 

 any means exhaust the Philippine forms of this genus. Several 

 other forms have been noted, and constitute a part of the citrus 

 collection at Lamao but are not here referred to, for the reason 

 that the material on hand is too incomplete to warrant their 

 description at this time. 



^ Acknoivledgements. The writer is greatly indebted to Mr. 



Southwick, superintendent of the demonstration station 



at Cebu, for his untiring zeal in repeatedly forwarding sets 



