I960] 



BOTANY OF THE GUAYANA HIGHLAND PART IV 



11 



ANTHOPHYA 



XYRIDACEAE 



Even before earlier comments on relationships within the Xyridaceae had 

 reached the printed page, we, already in the field, had collected specimens that 

 brought a new generic name to the Xyridaceae. This new finding requires a 

 reexamination of the familial integrity and generic composition of the Xyrid- 

 aceae. Also, in the meantime Dr. Sherwin Carlquist has had opportunity to 

 examine anatomically and morphologically freshly collected materials of the 

 family. We have drawn freely from the discussions in his paper, which accom- 

 panies the present work. 



In our earlier discussion 3 we had with some reservation held Abolboda and 

 the newly segregated Orectanthe, together with the type genus Xyris, to consti- 

 tute the Xyridaceae. The strongly marked massive (75-250 /x diam.), spheroidal, 

 non-apertnrate, spinose pollen grains of the first two seemed to give strong sup- 

 port to the position that they were familially inconsistent with Xyris, which has 

 small (47-53 /a diam., long axis), apertnrate, sulcate, spineless pollen grains. 

 These rather profound palynological discrepancies had led Erdtman 4 to suggest 

 that Abolbo$a (sensu lato) may be better referred to a monotypic family. 

 Xakai 5 , without presentation of argument, had earlier given the name Abolbod- 

 aceae valid status. 



On our recent visit to Cerro de la Neblina in south westernmost Amazonian 

 Venezuela, we collected in dwarf scrub vegetation of the often cloud-drenched 

 summit a yellow-flowered perennial monocotyledonous herb that we have called 

 Achlyphila, the name suggested by its habitat. Despite its non-xyrid habit, we 

 had concluded, because of similarity and identity of many features with those 

 of the Xyridaceae, and because of its inadmissibility to other associated monocot 

 families, that its affinities must lie with Xyris, Abolboda, and Orectanthe. 

 Supplementary data offered by Dr. Carlquist 's anatomical studies strengthen 

 and support this conclusion ; we now offer a restatement and redelineation of 

 the Xyridaceae, and propose herein a new genus, Achlyphila, the fourth for the 

 family. 



Xyridaceae Lindley, Nat. Syst. ed 2. 388. 1836. 



Xyrideae Kunth in Humb. & Bonpl. Nov. Gen. et Sp. (quarto text) 1: 225. 

 1816; folio text 1: 203. 1816 (both dates fide Barnhart). Endl. Gen. PI. 

 1: 123. 1841. Benth. & Hook. Gen. PI. 3: 841. 1883. Abolbodaceae 

 Nakai, Ordines, familiae tribi [etc.] in praelectionibus anni 1937 



3 Mem. N. Y. Bot. Gard. 10: 1-19. 1958. 



4 Pollen morphology and plant taxonomy 453, 454. 1952. 



•"'Ordines, familiae, tribus (etc.) in praelectionibus anni 1937. 



