1926] britton: west Indian plants 469 



slightly deflexed; petiole i-ij^ mm. long, minutely puberulous; 

 blade 9-13 mm. long, 4-8 mm. broad, elliptic or elliptic-oblong, 

 obtusely rounded at both ends or slightly and broadly cuneate 

 at the base, minutely apiculate at the apex, entire, glabrous on 

 both sides. Flowers in small branching or simple axillary ra- 

 cemes 3-10 mm. long, minutely bracteate, and minutely pu- 

 berulous on the axis, pedicel and calyx. Pedicels ]/2~ I mm. 

 long. Calyx-lobes 1 mm. long, oblong, rounded at the apex. 

 Corolla 5-lobed; tube 1 mm. long; lobes 1^/2 mm. long, oblong, 

 subacute, with thickened microscopically puberulous margins 

 within, glabrous on the back. Coronal lobes 5, arising from the 

 sinuses between the corolla-lobes, about 1 mm. long, linear- 

 lanceolate, acute, bent outwards just below the middle and 

 upcurved at the apex. Staminal column 1^2 mm. long, arising 

 shortly above the base of the tube of the corolla and exserted 

 from it, much dilated at the truncate apical part. Fruit not seen. 



Balandra Bay, Trinidad, {IV. G. Freeman njio). 



The genus Metastelma is one that urgently requires a thor- 

 ough revision, for as understood by modern authors and as de- 

 fined in Bentham & Hooker, Genera Plantarum 2: 755, it com- 

 prises three very distinct types of coronal structure, which in 

 other parts of the order are held to constitute generic distinction, 

 and there seems no valid reason why these differences should not 

 be considered of generic value in this case. The three types are: 

 1, Plants with the coronal lobes inserted at the sinuses of the 

 corolla. 2, Plants with the coronal lobes inserted at the base of 

 the staminal column. 3, Plants with the coronal lobes inserted 

 at the top of the staminal column. 



Originally the genus Metastelma was founded by Robert 

 Brown upon a plant collected in the Islands of St. Croix and St. 

 Christopher, having the coronal lobes inserted at the sinuses of 

 the corolla (type 1). This plant (M. parviflorum R. Br.) 1 find 

 upon comparison with the type to be identical with Thompson 

 499, collected on St. Croix, and M. Freemani, above described, 

 has the same type of structure and undoubtedly is a true species 

 of Metastelma. But modern authors seems to have understood 

 type 2 as being the typical structure of Metastelma. While 

 K. Schumann in Engler, Pflanzenfamilien 4 2 : 229 has placed 

 plants having the typical structure of Metastelma (i. e. type 1) 

 under the genus Irmischia, founded by Schlechtendahl in Lin- 

 naea 19: 738 upon a Mexican plant I have not seen, but which 

 from description may prove to be a typical Metastelma; in which 

 case Irmischia will rank as a svnonvm of Metastelma. 



