HAZEN: TRIMORPHISM AND INSECT VISITORS OF PONTEDERIA 461 
Darwin* in his book on heterostyled plants, published in 
July, 1877, reports a “third species of Pontederia” recently dis- 
covered by Fritz Müller, which had all three flower forms growing 
together in the interior of Brazil. I wasat first inclined to suppose 
that this was another species of Piaropus, for it seems strange that 
so acute an observer as Darwin should have been so bound by the 
conservative English conception of these plants current at that 
time, as to fail to distinguish between the large-flowered, many- 
seeded forms then beginning to be segregated on the continent as 
Eichhornia,t and the small-flowered, one-seeded Pontederia; but 
that this third species was a true Pontederia is attested by Fritz 
Müller himself six years later (op. cit. 297) when he also states 
that it was collected near Curitibanos in the highlands. This 
species may have been Pontederia rotundifolia L., or one of the 
imperfectly known allied forms; details of Darwin's description 
indicate that it could not have been our P. cordata L., or P. mon- 
levideensis Hort. (see note, p. 466) although the former is reported 
to grow as far south as Argentina, and the name of the latter 
suggests for it a South American origin. 
The first mention of heterostylism in our native pickerel-weed, 
Pontederia cordata, is found in a brief note by Mr. William Н. 
Leggettt a prominent early member of the Torrey Club, and 
probably first communicated in a meeting of the Club. In 
November, 1875, he reported having noted during a previous 
season an appearance of di- or trimorphism in this plant, but his 
somewhat inaccurate description, based upon examination of dried 
flowers, led Darwin to express doubt whether the species is really 
heterostyled. In August, 1877, the month following the publica- 
* Darwin, Charles. е different forms of flowers on plants of the same species, 
183-187. 1887. 
The very natural genus Piaropus (thick feet) was established by Rafinesque in 
of the literature for about four decades thereafter. If the principle of eese is 
ever to be maintained, there can be no justification for such provincialism in science 
as that practised by the Brussels Congress in ordering Rafinesque's ки 
name for a small strictly American genus published in Philadelphia to be rejected 
in favor of the Teutonic Eichhornia Kunth peso Plant. 4: 129. 1843) published 
six years = even though "e th's name was latterly attaining some degree of 
currency among continental wri 
Leggett, к H. Poneleria. dum Bull. Torrey Club 6: 62, 63. 1875. 
