acuminate

Acuminate is an adjective used primarily in botany to describe a leaf apex or other plant part that narrows gradually to a long, slender point. The term derives from Latin acuminatus, from acumen meaning sharp point. In leaf morphology, an acuminate apex tapers smoothly from the blade toward the tip, producing a tapering point that can be conspicuously long relative to the leaf size. This contrasts with an acute apex, which is sharp but shorter and less tapered, and with an obtuse apex, which is blunt or rounded.

The term is commonly applied to leaves and leaflets but can describe other plant structures such as petals or bracts when a pointed tip is present. In botanical identification, the presence of an acuminate apex can help distinguish species or varieties, particularly when combined with other leaf features such as margin, base, venation, and size.

Etymology-wise, acuminate comes from Latin acuminatus, the past participle of acuminare “to sharpen,” from acumen “sharpness.” In practice, acuminate is a standard descriptor in floras, horticultural guides, and plant identification keys.

Related terms include acute (a shorter, sharper point) and mucronate (having a small, abrupt point). The use of acuminate is largely confined to plant morphology, with occasional application to other contexts describing tapering forms.