20 



MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 



[vbb. 10 



only two, Spathanthus unilateralis (by the intrusion into Guayana of the var. 

 jenmani) and Rapatea paludosa, are eommon to both regions. Thus, of 80 spe- 

 cies, 62 are confined to Guayana, 16 occur without the periphery of Guayana, 

 and two species with their ranges chiefly outside barely intrude into Guayana. 

 These figures are summarized by genera in the following table. 



Total 



I. Subfam. Saxofridericioideae. 

 Tribe Saxofridericieae. 



1. Saxofridericia Rob. Schomb. 



2. Phelpsiella Maguire. 



3. Amphiphyllum Gleason. 



4. Stegolepis Kornicke. 



5. Epiphyton Maguire. 



Tribe Schoenocephalieae. 



6. Kunhardtia Maguire. 



7. Guacamaya Maguire. 



8. Schocnocephalium Seub. 



II. Subfam. Rapateoideae. 

 Tribe Eapateeae. 



9. Bapatea Aublet. 



10. Cephalostemon Rob. Schomb. 



11. Duckca Maguire. 



12. Spathanthus Desv. 



Tribe Mouotremeae. 



13. Monotrcma Komicke. 



14. Potarophytum Sandwith. 



15. Windsorina Gleason. 



16. Masclialocephalus Gilg & Schumann. 



No. Species Guayana Extra-Gnayana 



9 7 2 wholly 



1 1 



2 2 

 20 10 20 10 



2 2 wholly 



1 -1 



1 1 



5 5 



20 10 12 8 (2 wholly) 



5 14 wholly 



4 4 



2 i 1 1 



5 5 

 1 1 



1 1 ' 



1 1 wholly 



80 62 18 



Monocotyledonous Rapateaceae in the Naturlichen Pflanzenfamilien (1930) 

 are associated in the Unterreihe Bromeliineae, with the Thurniaceae and Brome- 

 liaceae. Hutchinson (1934) has placed the Rapateaceae with the Xyridaceae in 

 the Xyridales, and suggests derivation of the order, thus restricted, from or 

 through the presumptively more primitive Commelinales. Erdtman 11 states that 

 the pollens of the Xyridaceae and the Rapateaceae are "different." I am in- 

 clined to agree that affinities lie with the Xyridaceae, but that the Rapateaceae 

 are not immediately allied to them. 



There follows a preliminary arrangement of hierarchy within the family, 

 and a presentation of new genera and species which, it is hoped, .will serve as a 

 framework for an effective morpho-taxonomic monograph. 



Approximate figures. 



Pollen morphology and plant taxonomy 454. 1952. 



