154 



SHORT NOTES. 



MouRERA FLUviATiLis Aubl. — During a journey up the river 

 Essequibo and its tributary, the Potaro, from Bartica Grove to the 

 Tamatamari Falls, I had an opportunity of studying this most 

 interesting plant. The only way of ascending this river is in an 

 open boat, paddled by about twenty negroes ; and as at the many 

 rapids great delay occurs, during the dry season especially, there 

 was ample time for close examination of the plants ; it would be 

 difficult, too, to reach them from the shore, as they occur most 

 frequently in mid-stream, and are thus easily reached by swimming 

 from the boat attached to a rope. Nearly all the water plants in 

 the Essequibo belong to the Podostomacea;, lihynchulacis hydrO' 

 chicorium Tul. and E. macrocarpa Tul. being the most abundant, if 

 one may judge by their dried-up remains on the rocks that are 

 covered only at high water. These plants are confined entirely to 

 the rocl\S above extreme low water, whilst Mourera finviatilis is 

 restricted to a space of two or three feet below extreme low water, 

 as it would be fatal to the plant to be exposed to the air. The 

 rise from low to high water during the rainy season is very great, 

 and at highest water the Mourera would be from ten to twelve feet 

 below the surface. It is attached to the rocks very firmly by means 

 of a kind of thallus; the leaves are thick and succulent, from 12 to 

 18 in. long, resembling gigantic salad-chicory leaves, but of very 

 beautiful tints of red-brown and olive-green; it is very surprising to 

 see leaves of this character existing only in the most rapid parts of 

 the stream. As the water falls at the end of the rainy season, and 

 reaches within about two feet of extreme low water, the Mourera 

 begins to throw up its flower-spikes to a height of 18 in. to 2 ft. ; 

 the water still falls, the tips are exposed, and flowering commences, 

 and, as the flowering is from above downwards, by the time extreme 

 low water is reached the uppermost fruits are quite ripe and ready 

 to discharge their seeds. This must be done during the time the 

 water is at the lowest, for, as I before remarked, the plants exist 

 only on quite a narrow strip below extreme low water. The seeds 

 appear to fall on the rocks on the space just above low water that 

 is kept moist by capillary attraction, and they within a few hours 

 become covered with a gelatinous coating which enables them to 

 stick firmly to the rock till they are rooted. Growth is very rapid 

 indeed, as at the time of ray visit there were still some plants in 

 flower and also an abundant crop of seedlings that had grown from 

 the ripened seed. Processes are apparently thrown out very much 

 in the way of stolons, which enable the plant to gradually creep to 

 below low-water level into the space in which only it is able to 

 exist. The larger plants were all at the greatest depth, and 

 appeared to be annuals or perennials according to the fall of the 

 water; after flowering they invariably die. — Thomas B. Blow. 



Flora of Dorset (p. 121). — In the notice of the 2nd ed. of the 

 Flora of Dorset it is said, " Some transference of names may puzzle 

 future students of the Flora," and Fumaria parvijlora is cited 

 as an instance, which I think is the only one in the volume. I 

 relegated the Parley plant under that name to F. mnraUs in the 

 second edition, it having been erroneously placed there in the first. 



