Mau. 1891.] BOTANICAL SOCIETY OF EDIXBURGH. 81 



scattered about amongst the grass. Very abundant is a small 

 rubiaceous plant, very much resembling our common woodruff at 

 home. Compositse abound, and two species are particularly con- 

 spicuous — two yellow marigolds. Malvaceae are also very abundant 

 — about half a dozen species almost equally so — one of them a 

 most lovely little flower of the deepest crimson. Of Monocoty- 

 ledons, a beautiful yellow Iris claims attention. These, then, are 

 the flowers which form a conspicuous feature in the vegetation of 

 the palm-forest. For a few weeks they dot the ground in all 

 directions, while occasionally one encounters an expanse of open 

 literally carpeted with crimson mallows, scarlet and purple ver- 

 vains, yellow marigolds, or clover-like mimosas. 



" This ' palmar,' or palm-forest type of vegetation, is that which 

 covers the largest area — it extends, in fact, over thousands of 

 square miles. Another very distinct type is that of dicotyledonous 

 forest, but this is here confined to comparatively limited patches 

 of wood, many of them in the form of narrow belts, running more 

 or less parallel with the course of the river. Such woods are called 

 by the Argentines ' monte duro,' for the reason that they are com- 

 posed almost entirely of trees possessing very dense and hard 

 heart-wood. The surface of the ground generally slopes gradually 

 up to these montes, and they appear to be but little subject to 

 inundation. On entering such a piece of forest in this neighbour- 

 hood one finds oneself in a dense wood, composed of small and 

 slender trees, merely some 15-20 feet in height, and growing so 

 close together and so entangled as to make it scarcely possible to 

 make one's way through them. Most of these trees belong, in this 

 neighbourhood, to the kind called 'iianga pird' in Guarani, 'arrayan' 

 in provincial Argentine, a myrtaceous tree, with white flower 

 and small red fruit, looking externally very much like a miniature 

 tomato, and of delicate flavour. Its leaves are used as a substitute 

 for tea — a very poor one, in my opinion. A couple of spiny 

 acacias, a ' coulterie,' a shrub called ' pata,' and one or two other 

 Myrtacese go, though in much lesser numbers, to form, along with 

 the arrayan, the bulk of the forest. These are scarcely worthy of 

 the name of trees. At intervals, however, we have really fine 

 forest trees, which tower aloft to a height of 50 or 60 feet above 

 the general level of the trees below. These belong to various but 

 about here comparatively few species — the ' palo cruz,' (?) a tall, 

 slender bignoniaceous tree, with large yellow Tecoma-like flowers ; 

 the ' quebracho ' (Aspidosperma sp. ?) ; and the ' guayacan ' (Legu- 

 minosae) are, perhaps, the most conspicuous. The latter is a 

 magnificent timber, its heart- wood dark and heavy and very strong. 

 The ground Avithin the margin of the forest is dry, and is in most 

 places thickly grown with two large and very characteristic Bro- 

 meliaceae, both, 1 believe, species of ' karagnata.' The first of these 

 is the ' caragnate ' proper, a plant bearing a dense spike of 

 purple-petalled and red-bracted flowers, and a somewhat pine-apple- 



TRANS. HOT. SOC. VOL. XIX. F 



