THE TECHNOLOGIST. [April 1, 1865. 



404 



NOTES ON THE INDIGENOUS VEGETATION OF. NORTHERN 

 PERU. 



BY RICHARD SPRUCE, PH.D. 



Any person, even one accustomed to the study of and search for 

 plants, might travel through the whole extent of the deserts of 

 Piura and Sechura, and (excepting the strip of verdure along the 

 hanks of the rivers) would confidently assert them to be entirely 

 destitute of herbaceous vegetation ; and yet three kinds of herbs exist 

 there, which, burying themselves deep in the earth, survive through 

 the long periods of drought to which they are subjected. Some of the 

 smaller medanos, especially those under the lea of a low ridge of land, 

 may be seen to be capped with snowy white, contrasting with the yel- 

 lowish or greyish white which is the ordinary colour of the sand, and 

 yet at a short distance liable to be taken for sand a little whiter than 

 common. The whiteness, however, is that of the innumerable short 

 cylindrical 6pikes of an Amarantacea, whose stems, originating from 

 beneath the medano, ramify through it, and go on growing so as to main- 

 tain their heads always above the mass of sand, whose unceasing accumu- 

 lation at once supports and threatens to overwhelm them. 



The other two herbs of the desert are known to the natives, the one 

 as Yuca del monte, or wild Yuca, the other as Yuca de caballo, or Horse 

 Yuca, from their having roots like those of the cultivated yuca (Manihot 

 Aipi), or not unlike parsnips, but three times as large. Both roots are 

 edible, and the former is sometimes brought to market at Piura when the 

 common yuca is scarce. The Yuca de caballo is too watery to be cooked, 

 but is sometimes chewed to allay thirst by the muleteers and cowherds, 

 who detect its presence by the slightest remnant of the dried stump of a 

 stem ; for both kinds maintain a purely subterranean existence during 

 many successive years, and only produce leafy stems in those rare 

 seasons when sufficient rain falls to penetrate to the roots. A few ani- 

 mals that roam over the desert, such as goats, asses, and horses, obtain 

 a scanty supply of food and drink from these yuca roots, which they 

 scrape out with their hoofs. The fruit ot the Yuca de caballo may fre- 

 quently be seen blowing about the desert, looking more like a pair of very 

 long-hooked bird's claws than anything vegetable. It is an elongated 

 capsule with a fleshy pericarp (incorrectly described as a drupe) termi- 

 nating in a beak several inches long, and when ripe splitting into two 

 valves, which remain united at the base and curl up so as to resemble 

 claws or ram's horns. At Piura it is known by the not very apposite 

 name of espuclas, or spurs. In Mexico the fruit of an allied species is 

 called Una del diablo, or Devil's claws. The Yuca de caballo is a 

 Martinia, of the family of Gesnereae (or, according to some, of C'ystan- 

 dracea?). I was fortunate enough to see a single plant of it with leaves 

 and flowers in 1SG3, near the river Piura, on ground which the iuun- 



