Fruit structure of the genus Toricellia DC. (Tori-celliaceae) and its taxonomic position in the order Apiales
The genus Toricellia DC. with 2 species - T. tiliifolia DC. and T. angulata Oliv. - is represented by dioecious trees or shrubs with alternate exstipulate leaves and morphological differences between male and female flowers. Its fruit (pyrenarium) is ovoid or obliquely ovoid, crowned by a persistent calyx. Toricellia has 2-4-loculed yet 1-seeded pyrenaria, developed from the inferior ovary (pseudomonocarpous fruits). Outer walls of sterile locules have rounded openings. A very peculiar stone (“pyrene”) consists of two zones: the outer is very thick, consisting of multilayered lignified sclereids; the inner is one-layered, fiber-formed, inconspicuous. Thus, in species of Toricellia, the endocarp proper composes only the inner part of the pyrene, while the outer part is made of mesocarp elements, so the “pyrene” is of combined mesoendocarpic origin. The only seed is of the same shape as the locule - oblong and curved. Seed coat of a few cell layers. Some features shared by Toricellia and other related genera (Aralidium Miq., Griselinia Forst., Melanophylla Baker) are discussed along with Toricellia 's possible taxonomic relations.