Senegambia and Upper Guinea, on the west coast of Africa, form a low table-land, situated upwards of 3000 feet above the sea-level, and furrowed by deep gorges, in whose rocky beds the rivers roll and foam, fed by the waters of numerous streams. Grassy savannahs and wide cultivated areas are here inhabited by a numerous population. Several travellers have explored these regions; but all have specially applied themselves to make known the colossal plants which flourish therein, and those, first and foremost, which have a particular interest, either from their Anak-like stature or the manifold uses of their products. I shall have occasion to speak of the arborescent species which, in this part of the Old Continent, blend in immense and impenetrable forests. But owing to this very circumstance we possess few details respecting the plants which clothe the vast plains of Senegambia and Upper Guinea. We only know that there, as everywhere, the great family of the Gramineæ is largely represented. In general these species far exceed in height the plants which make the wealth and glory of our English meads; and they chiefly belong to the tribe of Paniceæ. A legion of Cassias inhabit the low fresh hills of the Senegambian lands; and some are held in high estimation for their fruit, as the Cassia, or Senna, which is considered one of the most active purgatives. The species generally recognized as best adapted for medicinal purposes are those with oboval and those with obtuse leaves--_Cassia obovata_ and _Cassia obtusifolia_. The former is a perennial herbaceous plant, from one to two feet high, with smooth egg-shaped leaves and racemes of yellow flowers; the latter differs only in the form of its leaves, which are short and broad, or obtuse.