VOL. XXXVII.J PHILOSOPHICAL TRANSACTIONS. 50/ 



description of the plant that produces it, which he had not hitherto met with 

 to his satisfaction in any author. 



F. Pkiniier, in his book entitled Nova Plantarum Americanarum Genera, de- 

 scribes a genus he calls dorstenia, of which the Dr. found two species in the 

 West Indies; the roots of which are gathered and exported indifferently; as 

 being very much alike, both in appearance and virtues. One of these he thinks 

 may be called Dorstenia dentarias radice, sphondylii folio, placenta ovali ; the 

 other, Dorstenia dentariae radice, folio minus laciniato, placenta quadrangular! 

 at undulata. 



The first kind, fig. 4, pi. 12, seems to be the tuzpatli of Hernandez, p. 147. 

 Its roots, which are perennial, put forth in the month of May, or as soon as 

 it happens to rain, each 6 or 8 leaves 4 or 5 inches long, and as many broad, 

 cut into several segments almost as deep as the middle rib, somewhat after 

 the manner of the sphondylium. They stand on footstalks 5 or 6 inches 

 long; and from the middle of them come forth other footstalks somewhat 

 longer, sustaining each a strong sort of body, flat, and situated vertically, or 

 with one edge uppermost, which the Dr. has called placenta. In this species 

 it is of an oval figure, with its longer axis parallel to the footstalk. One 

 side of it is smooth and green, like the outside of the calyx in other plants; 

 but from the other arise a great many small yellow apices; and after they 

 are gone, several small roundish seeds begin to appear, which when ripe are 

 somewhat like those of gromwell or lithospermon. It grows in the kingdom 

 of New Spain, near old Vera Cruz, on the high ground, by the side of the 

 river. 



The second kind, fig. 5, has much the same number of leaves as the former, 

 but of a different figure: for, some of them are entire, and shaped like those 

 of a violet; others angular like ivy ; and some almost as much divided as the 

 leaves of the common maple. They are thin, and of a dark green colour, 

 and smooth, or have only a few, scarcely perceptible, hairs on the back. The 

 pedicles that sustain the flowers arise immediately from the root, as in the other 

 species, and attain to the same height of 6 or 8 inches. But the placenta 

 which sustains the flowers is in this kind quadrangular, waved about the edges, 

 and broader transversely than vertically. Yet the flowers and seeds themselves 

 are perfectly the same as in the other. The second kind grows plentifully 

 on the high rocky grounds about Campechy, where the Dr. gathered it in per- 

 fection in the beginning of Nov. 1730. 



The Dr. cannot guess why F. Plumier has called this a monopetaious plant: 

 for, that which the latter calls the petalum, and the former the placenta, is 

 of a green colour; and, which is of more consequence, sustains the seeds when 

 3 T 2 



