340 NOTES OF A BOTANIST 



few other perennial grasses, chiefly species of Panicum and 

 Paspalum, besides the Grama dulce (Cynodon dactyloii), originally 

 brought from Europe, but here so completely naturalised that, if 

 allowed to spread, it would exclude almost every other plant. It 

 is valuable as an article of fodder. A few annual grasses, chiefly 

 species of Eragrostis, grow about the outer margin of the vega. 

 Of sedges also (species of Cyperus and Scirpus) there are four 

 or five species. 



Other herbaceous or suffruticose plants are a tall Polygonum, 

 the handsome Typha Truxillensis, the Yerba blanca ( Teleianthera 

 peruviana\ several species of Chenopodium, including the strong- 

 smelling Paico ( Ch. ambrosioides and multifidum) ; a Cleome, a 

 Portulaca, Scoparia dulcis, a Stemodium, and three or four other 

 Scrophulariaceae ; a Melilotus, a Crotalaria, a pretty Indigofera, 

 with numerous prostrate stems spreading every way from the 

 root, and pink flowers, a Desmodium, a sensitive - leaved 

 Desman thus, a Sonchus, Ambrosia peruviana, and a few other 

 Compositse; a Datura, two species of Physalis, Dictyocalyx Miersit, 

 Hook. f. (exceedingly variable in the size and shape of its leaves), 

 and the ubiquitous Solatium nigrum ; Verbena littoralis, two 

 species of Lippia, Tiaridium indicum, a Heliophytum, three 

 Euphorbias, a small Lythracea allied to Cuphea, and a few- 

 others. 



In the river itself occasionally grows a Naias, in dense 

 masses, like those of Anacharis ahinastruin in English streams 

 and ponds. . . . 



Two mosses, both species of Bryum, are occasionally found 

 on the banks of the river Chira, and on the filtering-stones kept 

 in houses, but only in a barren state. 



I did not remain long enough in the country to witness the 

 full effect of the rains of 1864 on the desert. The first plant to 

 spring up, in the ravines leading down from the tablazo to the 

 valley, and then on the tablazo itself, were two delicate Euphorbia?, 

 distinct from those of the vega. A little later on they were fol- 

 lowed by a fragile dichotomously branched Scrophulariacea (which 

 is common on the coast to northward of Guayaquil) ; two viscid 

 Nyctagineae (species of Oxybaphus) with pretty purple flowers ; and 

 two or three grasses (one of them an Aristida), but very sparingly. 

 The Yuca de caballo (Martyniae sp.) also began to put forth its 

 leaves, but the Yuca del monte had not, up to the 2oth of April, 

 shown itself above ground. I had seen far more wonderful 

 effects of the rains of 1862 at Chanduy, where a desert nearly 

 as bare as that of Piura became clad in a month's time with a 

 beautiful carpet of grasses, of many different species, over which 

 were scattered abundance of gay flowering plants. Something 

 similar must have occurred this year to northward of the hills of 

 Mancora, for people who travelled between Amotape and Tumbez 



