s 



12 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN' [VOL. 10 



Inflorescence scapose, capitate or in one genus open ; perianth regular or 

 somewhat zygomorphic ; sepals 3 or 2, the posterior members often strongly 

 conduplicate and decussate ; petals 3, free to the base or the claws connate into 

 a tube; stamens opposite the petals, 3, the anthers more or less sagittate; stamin- 

 odia 3, penicillate or simple, or lacking; ovary superior, 3-locular and the 

 placentation axial, or unilocular with parietal or basal placentation ; styles 

 simple or divided ; ovule anatropous ; embryo erect, the endosperm more or less 

 prominent. 



Perennial, herbaceous, more often acaulescent or short-stemmed herbs ; leaves 

 rosulate or distichous, often decussate ; mostly of marshy or boggy habitats ; 

 four genera in tropical America, only Xyris also of pantropic and temperate 

 distribution. 



Type genus : Xyris Linnaeus. 



Key to the Genera 



1. Petals yellow, free to the base; stylar appendage lacking; pollen grains espinose; 

 seed globose-ovoid, vertically striate, usually biapiculate. 

 2. Rhizomatous, caulescent perennial herb; inflorescence open, the flowers pedicellate; 

 sepals 3, not keeled; staminodia lacking; pollen grains sphaeroidal, non-apertur- 

 ate. 1. Achlyphila. 



2. Non-rhizomatous, usually acaulescent herb; inflorescence capitate; sepals 3, the 



two lateral strongly compressed and keeled; staminodia conspicuous, penicillate; 



pollen grains usually elongate, aperturate, without spines. 2. Xyris. 



1. Petals more or less strongly united at the base into a tube; stylar appendage evident 

 or conspicuous; pollen grains spinose; seed compressed or subprismatic or obliquely 

 truncate and often obliquely striate. 



3. Caulescent perennial herb with rosulate or cauline leaves; corollas yellow, porrec- 



tate, irregular, exceeding 3 cm in length; seed much compressed, broadly winged 

 and usually mitten-shaped. 3. Orectanthe. 



3. Acaulescent (commonly) perennial herb with basal or rosulate, seldom cauline 

 leaves; corollas blue or sometimes white, essentially regular, 2 cm or less long; 

 seed prismatic, obliquely truncate. 4. Abolboda. 



Achlyphila Maguire & Wurdack, gen. now 



Inflorescentia terminalis, pauciramosa; floribus trimeris, pedicellatis, dis- 

 tichis bracteatis; sepalis 3, imbricatis, subaequalibus ; petalis 3, liberis, flabel- 

 linervatis; staminibus 3, petalis appositis, antheris extrorsis sagittatis, versatili- 

 bus; granis pollinis sphaeroideis, non-aperturatis ; staminodiis nullis; ovario 

 3-loculari, placentis axialibus; ovulis anatropis; stylo simplici; capsula septi- 

 cidali; seminibus sphaeroideo-ovatis, eis Xyridis superficialiter similibus. 



Herbae perennes rhizomatosae ; caulibus compressis foliosis; foliis distichis 

 equitantibus. 



Achlyphila from axAus, cloud or mist, <£tAos, loving, an indication of habitat, 



1. Achlyphila disticha Maguire & Wurdack, sp. nov. Fig. 1. 



Herbae perennes 30-40 cm altae, rhizomatibus horizontalibus ramosis tenui- 

 bus, 2-3 mm diam., nodis vulgo 2-4 mm separatis; caulibus foliosis glabris com- 

 pressis 1.5-3.0 mm latis, nodis 12-15 mm separatis; foliis numerosis, rigide 

 equitantibus, distichis; vaginis 4.5-6.5 cm longis, valde conduplicatis, in ligula 

 eonduplicata scariosa, lineari-lanceolata acumine 3-5 mm longo terminatis; 

 laminis 4-6 cm longis lineari-lanceolatis, acutis, conspicue aristatis, 2-3 mm 

 latis, glabris, marginibus minute granulari-scabridulis ; pedunculis solitariis 

 terminalibus, valde compressis 10-15 cm longis, ca. 3.5 mm latis, marginibus 



