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This adaptation power, which reaches its maximum in Iberis semper florens, is testified by
the possibility of living along the sea shores on account of some alophilous features
(crassulence).
From an anatomical point of view this group of plants is characterized by leaves with a
subcuticolar lining of mucillage and by the presence of stomata on the whole leaf surface,
probably it may also occur a particular type of hairiness. Prom a taxonomical point of view
these species are well defined and more or less isolated.
2. Shrubs of evergreen xerophilous type (see for ex. Figs. 102, 116, 118): presumably they
originated at a higher mountain altitude, above the persistent fogs, with exposures to
longlasting insolation, in opposition to the previous ones.
The species are much like those of the mediterranean shrubs of today (stenophillous and
microphillous types) and have several features in common with them. They differ from these
mainly on account of their deficiency of well defined growth rythm. This characteristic is
indicative of a daily climate rather than of a seasonal one. Intermediate stages between this
type and the proceeding one may be found. The following plants belong to this category: A
sperula rupestris, Lythospermum rosmarin i folium, Satureja fruticulosa, Helichrysum
pendulum, Thymus nitidus. As regards their structures these plants show the localisation of
the stomata on the underside of the leaf. Two types of leaf can be found: with hairy and
hairless upper surface. In the latter the mucilages tend to sink from the outer cell wall
(subcuticular) to the inner one, close to the palisade. As regards their taxonomy these species
are only feebly differentiated and in some case they must be interpreted only as varieties.
They do not show any particular adaptation to the habitat of vertical rocks, for which they
are only preadapted.
The species mentioned till now are all west mediterranean, but also two east mediterranean
plants belong to this group and show some peculiar characteristics; Daphne oleifolia (with
leaves of montane Rhododendron type, Figs. 131, 132, 133) is characterized by growth
without resting periods, by its fittness to marshy habitats and its defined taxonomical
position. Its range covers Colchide, Tuscan-Latial Maremma, besides some relict montane
localities. Erica sicula (Figs. 134, 136) is characterized by a restless growth, a rather strong
degree of xerophily of the leaf and a high taxonomical differentiation.
Evidently we deal with ancient plants, expecially Erica sicula, originated in a well
characterized daily climate, without any resting season along the year.
3. Herbs of mesophilous type: for this group we have been compelled to base our researches
only on chorological data and possibly on the behaviour of these plants in their present
habitat. This group comprehends some montane plants chiefly distributed in the Atlas
mountains of the North West Africa (Hypochaeris laevigata, Fig. 119, and Ranunculus
rupestris, Fig. 126). In this group we find also a bulbous plant (Scilla Hughii, Fig. 124) with
mediterranean characteristics and an accentuated degree of mesophily in opposition to the
allied Scilla elongata; we find here too Brassica macrocarpa (to be considered much more a
big perennial herb than a shrub) with characters of a mesophilous mediterranean plant and a
certain degree of alophitic adaptation and finally Lagurus ovatus var. vestitus a primitive
entity, compared with the omnimediterranean Lagurus ovatus. All these plants live more or
less exclusively on the vertical cliffs, although they do not seem to possess any particular
adaptation or preadaptation to the rocky habitat.
4. Herbs of mediterranean-atlantic type: we have only one representative of this
group: Erodium maritimum. This plant probably originated in the higher altitudes of the
mediterranean mountains when the climate of the mediterranean basin was of a tropical type,
from there Erodium maritimum spread down and along the atlantic european coasts, where
today it has to stand a climate with a scarse seasonal differentiation. This plant shows,
like Daphne oleifolia, a certain contact with the marshy habitats.