APR. 1960 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN 10(2):6o-117 



ANATOMY OF GUAYANA XYRIDACEAE: ABOLBODA, ORECTANTHE, 



AND ACHLYPHILA 



Sherwix Carlquist 



Claremont Graduate School, Raneho Santa Ana Botanic Garden, Claremont, California 



The discovery of exceptionally interesting new entities referable to 

 Xydridaceae in the Guayana Highland by Maguire and his colleagues (Maguire, 

 Wurdack et al. 1958, 1960) has led to a reappraisal of the limits of the family 

 and its relationships within the monocotyledons. On another level, there are 

 problems of generic and specific differences and relationships and their evolu- 

 tionary implications. Anatomical studies are important aids in solving these 

 problems. Dr. Maguire, who has organized studies on these taxa, has recognized 

 the helpfulness of anatomical data and has provided me with an excellent col- 

 lection of suitable material. I should like to express sincerest appreciation to 

 him for his gratifying interest in the studies recounted below, his generous 

 sharing of material with me, and his invitation of this contribution. Of par- 

 ticular significance is the fact that the writer reached the conclusions set for- 

 ward at the end of this paper on the basis of anatomical material alone. Dr. 

 Maguire and I exchanged manuscripts when our studies were completed so that 

 we -could take advantage of each other's findings in a final presentation, but the 

 great similarity in our conclusions, based on different methods of study, derives 

 from the fact that anatomical features show the same patterns of likeness and 

 diversification with reference to the taxonomic system as do features of gross 

 morphology. I acknowledge with pleasure Dr Maguire 's interest in my in- 

 dependent development of such facts, and his use of these when they became 

 available to him. If there had been any major divergences of opinion, we should 

 have exposed these and attempted to resolve them, but in fact, no such dis- 

 agreements in interpretation of materials did occur. 



MATERIALS AND METHODS 



Both liquid-preserved and herbarium materials were given to the writer. 

 Herbarium material was treated with warm 2.5 per cent aqueous NaOH to 

 expand it to its natural proportions, washed, and stored in 50 per cent ethyl 

 alcohol. Both liquid-preserved and treated herbarium material were embedded, 

 sectioned, and stained according to the techniques described earlier by the 

 writer (1958). Pollen preparation techniques are described below in connection 

 with that topic. 



The specimens studied are listed below. All specimens are represented by 

 a mounted collection in the New York Botanical Garden Herbarium. Taxa 

 recognized correspond with those of Maguire, Wurdack, et al. (1958, 1960). 



Liquid-preserved, assorted parts: Abolboda acaulis Maguire, Maguire & 

 Politi 27700, Maguire 32820, Maguire 33730, Maguire et al. 40669; A. acicularis 

 Idrobo & Smith var. acicularis, Maguire et al. 41439; A. americana (Aublet) 

 Lanjouw, Maguire et al. 41537; A. ciliata Maguire & Wurdack, Maguire et al. 

 42420; A. linearifolia Maguire, Maguire et al. 41680; A. macrostachya Spruce 

 ex Malme var. angustior Maguire, Maguire et al. 41541; A. macrostachya Spruce 

 ex Malme var. macrostachya, Maguire et al. 41446 ; A. macrostachya Spruce ex 



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