ON A SPECIES OF IPOMCEA, AFFORDING TAMPICO JALAP. 849 
The unsettled condition of Mexico, and the fluctuations of commerce, have alternately 
depreciated or enhanced the value of jalap, and have led to the occasional importation 
of other roots possessing more or less of the characters of the true drug. Of such kinds 
of jalap, one of the most remarkable is a tubercule imported a few years ago for the first 
time from Tampico, and thence called Tampico jalap * This drug has been extensively 
brought into the market (that is to say, by hundreds of bales); and though it is less 
rich in resin and less purgative than true jalap, yet, on account of its lower price, it has 
found a ready sale, chiefly in continental trade. 
As the botanical origin of this so-called Tampico jalap, and even its place of growth, 
were completely unknown, I addressed a letter, in November 1867, to my friend Hugo 
Finck, Esq., Prussian \ice-Consul at Cordova (Mexico), begging that he would, if pos¬ 
sible, procure for me some information on the subject. Mr. Finck at first expressed strong 
doubts as to Tampico jalap being anything else than the root of Batatas jalapa, Chois., 
known in Mexico as Purga macho. Upon inquiry, however, he ascertained that such 
coula not be the case, but that it is a production of the State of Guanajuato, where it 
grows along the Sierra Gorda, in the neighbourhood of San Luis de la Paz. At this 
town, and in the adjacent villages, it is purchased of the Indians and carried by the 
muleteers to Tampico, where it is known as Purga de Sierra Gorda . 
All attempts to procure specimens of the plant were for some time fruitless, chieflv 
owing to the difficulty of finding any one in the district who could be induced to take 
the needful trouble. The perseverance of Mr. Finck and his friend, Mr. E. Benecke, 
Consul-General for Prussia in the city of Mexico, overcame at length this obstacle, but 
only to meet with others hardly less embarrassing. The first lot of specimens dispatched 
from Guanajuato was stolen from the mail; the second shared the same fate; while a 
tliird, which included live tubercules, was, by successive detentions on the way, fullv 
five months in reaching England. The box, however, came to hand in June last; and 
amid a mass of damp earth and decaying matter, I had the satisfaction of discovering 
one solitary tubercule exhibiting signs of vitality. This, placed in a greenhouse and 
carefully nursed, soon began to grow with rapidity, and, on removal to an open border, 
produced a tall and vigorous plant, whiuh towards September showed signs of flowering. 
It was then taken up and replaced in the greenhouse, where it blossomed freely in 
October last, but did not mature any seeds. Accompanying the tubercules, but of 
course in a separate box, my correspondent sent some pressed and dried specimens from • 
Guanajuato, which corresponded perfectly with the growing plant. 
Having ascertained from the study of these materials, that the plant belonged to the 
genus Ipomcea, I endeavoured to identify it with some species described in the ‘Pro- 
dromus’ of De Candolle, or in the subsequently published ‘Anuales’ of Walpers, but 
without success. Neither w’as I able to find any corresponding specimen in the herbaria 
of the British Museum or of the Royal Gardens of Kew. In the Paris Museum there is 
a plant, collected by Galeotti on the lofty Cordillera near Oaxaca, which, so far as a 
scanty specimen enables me to judge, accords precisely with that received from Mr. 
Finck. It bears a number which is not mentioned in the enumeration, by Martens, of 
Galeotti’s Convolvulacece (contained in the ‘Bulletin de l’Academie Royale de Bruxelles’); + 
and I therefore conclude that it is unnamed. Under these circumstances, I have drawn 
up the folio-wing diagnosis and description of the plant, which I propose to call Ipomcea 
simulans. The specific name is chosen in allusion to the remarkable similarity which 
the plant bears in foliage and habit to the true jalap ( Ipomcea purga , Hayne), not to 
mention the resemblance of its tubercules. The funnel-shaped corolla and pendent 
flower-buds of the Tampico jalap-plant are quite unlike the corresponding parts of I. 
purga , and furnish a ready means of distinguishing the two species:— 
Ipomcea simulans, sp. nov. Radice tuberosa, caule volubili herbaceo glabro, foliis 
ovatis, acuminatis, cordatis v. sagittatis, indivisis, pedunculis unifloris solitariis, 
sepalis parvis. 
Hub. in Andibus Mexican is Sierra Gorda dietis, prov. Guanajuato (fide cl. Finck); 
in regione frigida ad ped. 8000 prope Oaxaca (B. Galeotti , n. 1369 !). 
* I cannot, at least, trace this jalap to have been offered in commerce as a distinct sort 
earlier than about five or six years ago. 
f Tome xii. pt. 2 (1845), p. 257. 
