Sigmatostalix graminea (Poepp. & Endl.) Rehbf. 
in Bot. Zeit. 10: 769, 1852. 
Basionym: Specklinia graminea Poepp. & Endl. Nov. 
Gen. ac Sp. 1: 51, 18386. 
Synonym: Stgmatostaliv peruviana Rolfe in Kew Bull. 
371, 1910. 
Sigmatostaha pusilla Schltr. in Fedde Rep. 
10: 892, 1912. 
Sigmatostahx bicornuta Rolfe in Kew Bull. 
342, 19138. 
Petalocentrum pusillum Schltr. in Fedde 
Rep. 15: 145, 1918. 
Petalocentrum angustifolium Schltr.in Fedde 
Rep. 15: 145, 1918. 
Petalocentrum bicornutum Schltr. in Fedde 
Rep. Beih. 9; 179, 1921. 
Unfortunately, until recently we have had no clear 
understanding of the floral morphology of Sigmatostalia 
graminea, although it is the type of the genus. The 
original illustration of this species by Poeppig is very 
misleading, especially for floral details. As a matter of 
fact, they maybe called the product of pure imagination. 
Reichenbach in Yenia Orchidacea published new details 
for Sigmatostaliv graminea, which he claimed to have 
based on examinination of the original material. If the 
claim be correct, then Reichenbach must have examined 
some poorly preserved flowers. In 1964, I studied Poep- 
pig’s original material and made careful dissections. 
These dissections revealed a hitherto unknown feature 
of this species, namely a small, tooth-like projection on 
the external side of the petals. This very character was 
employed by Schlechter in establishing Petalocentrum 
as a distinct genus beside Sigmatostahw. Consequently, 
the genus Petalocentrum is untenable. A correct illus- 
tration of Sigmatostalix graminea is to be found in Medde 
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