The vegetation became still more interesting when we left the flat bottom of the valley, and began to ascend on drier ground, between tangled masses of bushes that formed a sort of thick hedge on either side of the track. For the first time in South Marocco, we saw two species of _Clematis_—_C. cirrhosa_ and _C. Flammula_,—along with several other Mediterranean species; but our minds were especially exercised by a little bush with slender twigs and pinnate leaves, which, in default of flower or fruit, we were at first unable to refer to its place in the natural system. It turned out to be a curious species of ash, first found in the plateau region of Southern Algeria, appropriately named by M. Cosson _Fraxinus dimorpha_. As long as it remains a bush, with numerous twiggy stems, the leaflets are blunt and rounded; but when it becomes a shrub, with a stout trunk, it throws out leaves that approach in form those of the flowering ash. We nowhere saw it in this condition in Marocco, and only by the help of Algerian specimens could we have suspected the identity of the two forms. Among many thorny bushes we saw here one, first gathered the day before, near Tasseremout, which Hooker at once pronounced to be a _Celastrus_. This was first found in the South of Spain, and described as _C. europæus_ by M. Boissier, but is in truth one of the many forms of _C. senegalensis_, a widely-spread tropical species, that extends from India to the west coast of Africa. Among other novelties, we here saw, for the first time, a little annual stonecrop (_Sedum modestum_, Ball), that nestles in hollow places under large stones, or about the roots of trees; but the most curious trophy of our day’s work was a miniature bramble, lying flat on earthy banks, with small, mostly undivided leaves, and very few minute prickles. It is possible that the imperfect fruits that we saw had been dried up by the sun; but it seems more likely that this belongs to the group of dry-fruited brambles—the genus _Dalibarda_ of some botanists—hitherto known only in America and Eastern Asia. We passed near to several villages; but, as a rule, the valley tracks in the Great Atlas are carried on one side, and do not approach near to the houses. The valley grew narrower as we advanced, and the moderately steep slopes on either hand were covered with small trees of _Callitris_, and _Juniperus phœnicea_, none of them more than about thirty feet in height. If this country were administered by people capable of taking thought of its future prosperity, the former tree might undoubtedly become an important source of wealth. The beauty of the wood, if it were only allowed to attain a sufficient size, would always secure a ready market, even though it never reached the extravagant price which, under the name of citrus wood, it obtained in the days of Imperial Rome. The only use which it serves in Marocco is the production of gum Sandrac, of which a small quantity is exported to Europe.