A TRIANDROUS FORM OF PSILOCHILUS 



MACROPHYLLUS 



Psilochilus macrophyllus (Lindl.) Ames comb. nov. Pogonia 

 macrophylla Lindl. in Ann. & Mag. Nat. Hist. ser. 3, 1 (1858) 

 335. Pogonia physurifolia Reichb.f. in Nederl. Kruidk. Arch. 4 

 (1858) 324. 



Among the specimens of Psilochilus macrophyllus from Gre- 

 nada, B. W. I. a single plant was found in which the gynoste- 

 mium was triandrous in a very interesting way, the supplemen- 

 tary anthers being lateral, one on each side near the base of the 

 stigma. These supplementary anthers probably represent nor- 

 mally suppressed members of the outer androecial whorl, which 

 often occur as staminodia in species of Orchis, Habenaria, etc. 

 When in natural position the anther cells face inward toward 

 the stigma and conceal it. Each anther is supplied by a vascular 

 strand that continues into it as a median nerve. The pollen 

 masses taken from the supplementary anthers consist of tetrads 

 that appear to be quite normal, the extine exhibiting the retic- 

 ulations or pits found in the pollen of normal anther cells of 

 the species. Aside from the abnormal condition of the gyno- 

 stemium the flowers examined appeared to be perfectly normal. 



As far as I have been able to ascertain, a triandrous condition 

 in Psilochilus macrophyllus has not previously been recorded. 

 (Plate 110.) 



Grenada, B. W, I., Azima Mountain, W. E. Broadzoay, November 18, 

 1905. Woods, in damp flat ground. (Herb. Ames 7724.) 



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