66 
with softly woolly leaves, that the original description of Croton 
senegalense, Lamk, applies. Yet it is one of the two with leaves 
adpressed-hoary on the undersurface which Lamarck has cited as 
his type, and the example of ‘ Adanson n. 145’ in the Jussieu 
herbarium has been written by Lamarck himself as ‘ Croton sene- 
galense Lamk encycl.’ The specimen which agrees with 
Lamarck’s description bears no endorsement in Lamarck’s hand- 
writing; beyond the words ‘Herb. de Galam 60’, written by 
Adamson, it only has the word ‘ Croton ’ written by A. L. Jussieu. 
The plants represented by this specimen and by ‘ Adanson n. 
145” are certainly closely related. This, however, does not 
alter the fact that, under Croton senegalense, Lamarck has des- 
cribed one plant and cited another as the basis of his species. 
In 1790 Vahl (Symb. Bot. p. 78), dealt more satisfactorily 
than Zoega did in 1775 with the two species of Chrozophora 
collected by Forskil in Egypt. The one which in Forskals list 
stood as ‘490. Croton tinctorium,’ Vahl described as Croton 
plicatum, and the actual specimen at Copenhagen which bears the 
legend ‘©. tinctorium Forsk. Cent. vi. p. 162,’ has been written 
up by Vahl as C. plicatum. By some inadvertence, however, 
Vahl, when describing this species, either failed to note that it 
had been collected at Gizeh, or failed to realise that Gizeh is in 
Egypt. By giving ‘ Arabia,’ where C. plicatum has never yet 
been collected, as the home of the species, Vahl has led more than 
one subsequent author astray. The plant, which in F orskal’s 
that this error was not due to any confusion by Vahl 
between the plant collected at Gizeh which Forsk&él named 
C. tinctorium and the plant collected at Lohaja in Arabia 
to which Forskél gave the same name. It is true that 
Vahl did not take up ‘ 563. Croton tinctorium?’ in the ‘ Sym- 
belae.’ It is also true that one of the two examples of this 
gathering now in the Copenhagen herbarium, which originally 
formed part of the Schumacher herbarium, was not written up by 
Vahl. But the other example of the Lohaja plant at Copenhagen 
bears the name, in Vahl’s handwriting, ‘Croton tinctorium F.’ 
This endorsement shows that Vahl was aware of the treatment 
Forskal had- proposed for this plant, and suggests that Vahl 
realised that it is different from C. tinctoriwm, Linn. 
In 1794 the brothers Russell published a list of Aleppo plants 
(Aleppo ii. p. 265) one of these plants being Croton tinctorium, 
Linn. Their specimens, now in the British (Natural History) 
Museum, show that they included under the species at least one 
specimen which, while closely allied to, yet differs specifically 
from the true ‘ Tournesol ’ figured by Clusius and Gesner. 
* 
