← Glossary Morphology trifoliate Having three leaflets, as in clover or poison ivy. A compound leaf divided into exactly three parts. Plants Using This Term (2) Toxicodendron pubescens — Atlantic Poison Oak Toxicodendron radicans — Eastern Poison Ivy Related Terms achene acuminate alternate annual axillary basal berry biennial bract calyx capsule cauline clasping cordate corolla crenate cyme cypsela deciduous dentate drupe entire evergreen glaucous inflorescence lanceolate ligulate lobed opposite ovary palmate panicle pappus pedicel perennial petiole pinnate pubescent raceme rachis rhizome rosette sepal serrate sessile silique spadix spathe spatulate stamen succulent taproot ternate thallus umbel undulate whorled