162 Proceedings of the Royal Irish Academy. 



Erica Tetralix. 1 . 

 Pedicularis sylvatica. 1. 

 Melampyrum pratense. 1. 

 Empetrum nigrum. 3. 

 Listera cordata. 2. 

 Juncus effusus. 1. 

 Luzula campestris. 1. 

 iiartlieciuiii ossifragum. 1. 

 Eriophorum vaginatum. 2. 

 E. angustifolium. 1. 

 Carex glauca. 3. 



C. pilulifera. 2. 

 Anthoxanthum odoratum. 1. 

 Deschampsia flexuosa. 2. 

 Molinia caerulea. 2. 

 Triodia decumbens. 1. 

 Pteris Aquilina. 2. 

 Lastrea dilatata. 2. 

 Racomitrium lanuginosum. 2. 

 Polytrichum. 1 . 

 Cladonia rangiferina. 3. 



The Vaccinum Association. (V.) 



Although Vaccinium Myrtillus is a constant ingredient of all the 

 hill associations from Ulex Gallii upward, the wet Scirpus ground (to 

 be described presently) excepted, it never grows luxuriantly except 

 on well-drained, rocky slopes. These vary greatly in elevation, from 

 a few hundred feet on Bray Head to over 2000 feet on the hills. 

 Over any considerable area, however, it becomes dominant only in 

 one locality in the district — namely, along the summit of the pre- 

 cipitous slopes that overlook Upper and Lower Lough Bray, at an 

 elevation of 1600 to 1800 feet. Here a characteristic " Vaccinium 

 edge" is developed, where the higher, wet Scirpus moors give way at 

 first to a narrow fringe of fairly typical Calluna ground, and as soon 

 as the broken granite cliffs are reached, Vaccinium Myrtillus becomes 

 the dominant plant among the rocky edges and slopes. 



The association here is composed as follows : — 



Yaccinium Myrtillus. 

 Calluna vulgaris. 

 Vaccinium Vitis-Idaea. 

 Oxalis Acetosella. 

 Galium saxatile. 



The Scirpus Association. (S.) 



In the lower parts of the moorland zone, especially on the flatter 

 and badly-drained places, such as the larger areas on the slopes of 

 Kippure at the south end of Glenasmole, the Calluna moor is gradually 

 displaced by a true bog association in which the predominating plant 



Melampyrum pratense. 

 Luzula maxima. 

 Deschampsia flexuosa. 

 Blechnum Spicaiit. 



