42 MEMOIRS OF THE NEW YORK BOTANICAL GARDEN [VOL. 10 



J. A. Steyermark 4' J- J. Wurdaek 938 (US), 1099 (NY). Diomma species B : B. Maguire, 

 J. J. Wurdaek # C. Maguire 42329 (US, Y), 42315 (US, Y). 



Sohnreyia excelsa Krause: A. Ducke 8 (Y), 1180 (US, Y), s. n. (US, MG 15702), g. n. 

 (US, KB 20472). 



Wood specimens were available of Diomma species B, B. Maguire, J. J. Wurdaek 4' C. 

 Maguire 42315, and of Sohnreyia excelsa, A. Ducke 8. Preserved material of Diomma was 

 available as follows: fruits and petiole portions, B. Maguire, J. J. Wurdaek 4" C. Maguire 

 42329; flowers, leaf and petiole portions, B. Maguire, J. J. Wurdaek 4' C- Maguire 42315; 

 flower buds, J. A. Steyermark 4" J- J- Wurdaek 1099. 



GENERAL MORPHOLOGY 



In the course of our investigations several new structural features and ar- 

 rangements of sex in Diomma and Sohnreyia have come to light. Because we 

 probably have had more specimens for study than had Harms, Engler, or 

 Krause, it is possible to show certain heretofore unreported characteristics to 

 good advantage. For the sake of the discussions which follow, it is of importance 

 to set down these additions to the knowledge of the genera in question. 



Diomma. 



1. All species of Diomma apparently are polygamous. However, because of 

 the relative paucity of flowering material, the kinds of flowers that occur in the 

 different species are uncertain. In D. ulei only female flowers were found; in D. 

 fruticosa and Diomma species B, only male flowers were seen. In Diomma species 

 A, both male and female flowers were observed in the same inflorescence. 



2. Sepals, and often petals, are provided with a tiny glandular cavity at 

 their apices. 



3. The filaments of stamens in species of Diomma possess 2 lateral, wing-like 

 expansions (appendages?) in the lower half (fig. 2A-D). These have free, cil- 

 iate, dentiform tips and are usually densely villous on the inner surface. Unfor- 

 tunately, only female flowers of D. ulei were on hand, and the staminal filaments 

 (stamens here are apparently non-functional) here did not possess distinct 

 wing-like portions. However, the bases of the filaments were more or less slightly 

 broadened and ciliate (fig. 2 A, B). 



4. Qvaries of female flowers (fig. 1) are subsessile and are situated on a tiny 

 pedestal or rudimentary gynophore. This pedestal bears 5, unequally large, 

 cushion-like swellings. These are sometimes more or less confluent and appar- 

 ently are nectariferous. A single very short style which terminates in 2 large, 

 discoid to subcapitate stigmatic lobes is present. The stigmata are fleshy and 

 papillose, and may be coherent or actually connate so as to produce a single, 

 deeply bilobed structure. Stamens are somewhat shorter in female than in male 

 flowers. Male flowers possess pistils with reduced ovaries and rudimentary stig- 

 mata, Interestingly, in these flowers, the ovarian pedestal, which is inconspicu- 

 ous in female flowers, forms >a more or less conspicuous, broad, gynophore. 



5. Within the dorsal wall of each carpel there is an elongate secretory cavity, 

 narrow at the apex and more or less bulbous at the base, which is filled with 

 yellowish contents (fig. 1A-C). 



There has been some doubt cast on the presence of certain characters in 

 Diomma upon which we can now elaborate. For example, there is no question 

 that the pendulous ovules of Diomma are indeed apotropous, that the raphe is 

 dorsal, and that the micropyle is directed upward (fig. 1A). 



