155. So the palmate leaf, if again compounded in the same way, becomes _twice palmate_, or, as we say when the divisions are in threes, _twice ternate_ (in Latin form _biternate_); if a third time compounded, _thrice ternate_ or _triternate_. But if the division goes still further, or if the degree is variable, we simply say that the leaf is _decompound_; either palmately or pinnately decompound, as the case may be. Thus, Fig. 161 represents a four times ternately compound (in other words a _ternately decompound_) leaf of a common Meadow Rue. [Illustration: Fig. 161. Ternately decompound leaf of Meadow Rue.] 156. When the botanist, in describing leaves, wishes to express the number of the leaflets, he may use terms like these:-- _Unifoliolate_, for a compound leaf of a single leaflet; from the Latin _unum_, one, and _foliolum_, leaflet. _Bifoliolate_, of two leaflets, from the Latin _bis_, twice, and _foliolum_, leaflet. _Trifoliolate_ (or _ternate_), of three leaflets, as the Clover; and so on. _Palmately bifoliolate_, _trifoliolate_, _quadrifoliolate_, _plurifoliolate_ (of several leaflets), etc.: or else _Pinnately bi-_, _tri-_, _quadri-_, or _plurifoliolate_ (that is, of two, three, four, five, or several leaflets), as the case may be: these are terse ways of denoting in single phrases both the number of leaflets and the kind of compounding. 157. Of foliage-leaves having certain peculiarities in structure, the following may be noted:-- 158. =Perfoliate Leaves.= In these the stem that bears them seems to run through the blade of the leaf, more or less above its base. A common Bellwort (Uvularia perfoliata, Fig. 162) is a familiar illustration. The lower and earlier leaves show it distinctly. Later, the plant is apt to produce some leaves merely clasping the stem by the sessile and heart-shaped base, and the latest may be merely sessile. So the series explains the peculiarity: in the formation of the leaf the bases, meeting around the stem, grow together there. [Illustration: Fig. 162. A summer branch of Uvularia perfoliata; lower leaves perfoliate, upper cordate-clasping, uppermost simply sessile.] [Illustration: Fig. 163. Branch of a Honeysuckle, with connate-perfoliate leaves.] 159. =Connate-perfoliate.= Such are the upper leaves of true Honeysuckles. Here (Fig. 163) of the opposite and sessile leaves, some pairs, especially the uppermost, in the course of their formation unite around the stem, which thus seems to run through the disk formed by their union. [Illustration: Fig. 164. Rootstock and equitant leaves of Iris. 165. A section across the cluster of leaves at the bottom, showing the equitation.]