Marsh , and its Relations to Evaporation , drV. 279 
Type (3). Inflorescences exposed as in the last type. The aerial 
stems are more completely foliated than in (2), and the decrease in the size 
of leaves (after the maximum) is, on the whole, much more gradual. As 
leaves of a fair size occur on most parts of the erect shoots, the transpiring 
organs are found in most layers of the vegetation. If the latter is dense, 
the lower leaves frequently die early, and the functional leaves are then 
comparatively high on the stem. In this state the plants approach those of 
type (4); e. g. Thalictrum flamnn , Spiraea Ulmaria (Text-figs. 4 and 6 ), 
Lathy rus palustris , Car duns palustris , Eupatorium canndbinum , Valeriana 
officinalis , &c. 
Type (4). Inflorescences exposed. The largest leaves are formed in 
relatively high layers of the vegetation. The lower leaves on the erect 
stem are small, frequently scale-like ; e. g. Lysimachia vulgaris (Text-figs. 
1 and 6), Ly copus europaeus , Ly thrum Salicaria (Text-fig. 6), Phragmites 
communis (Text-figs. 4 and 6), &c. 
Type (5). The grass or sedge type. Here the inflorescences are 
exposed as before. The leaves are formed at low levels, but owing to their 
length and vertical growth usually attain to the general vegetation level. 
On account of the numerical superiority of the plants of this type, they 
dominate the vegetation here dealt with, and impart to it its characteristic 
physiognomy 1 ; e. g. Cladium Mariscus (Text- fig. 4), Schoenus nigricans , 
Carex spp. (Text-fig. 6), Molinia coerulea , and other grasses, J uncus spp. 
(Text-fig. 6), Iris Pseudacorus , &c. 
To sum up, the inflorescences of the great majority of the species are 
placed at or near the general vegetation level (sometimes above or some- 
times just below). This is, of course, to be correlated with pollination 
requirements. On the other hand, the transpiring organs are found at very 
various levels, but rarely project far above the general vegetation level. 
Roughly, one may say that, of the above groups, (1) and (2) habitually 
have their leaves in sheltered, often shady positions ; while the leaves 
of the plants of the remaining groups are, in varying degrees, more exposed. 
As examples of plants which usually have more or less exposed leaves may 
be mentioned Spiraea Ulmaria , Lythrum Salicaria , Lysimachia vulgaris , 
J uncus spp., Cladium Mariscus , and Phragmites communis. Amongst the 
habitually sheltered plants are Lastrea Thelypteris , Ophioglossum vulgatum , 
Orchis incar nata, Hydrocotyle vulgaris , Valeriana dioica , &c. 
Although the plants of the lowest strata often exhibit shade characters 
in their leaves, it is important to distinguish between f shelter 5 and ‘ shade ’ 
plants. Many of the usually sheltered plants are not necessarily shade 
plants at all, as they may grow exposed to full sunlight. 2 They then form 
1 Yapp, 1. c., p. 66 . 
2 Cf. Leist (’90), pp. 182 et seq. This author found that there is a general agreement in size 
and structure between the leaves of alpine plants, in open, sunny situations, and those of lowland 
