Goethalsia is a monotypic genus of flowering plants belonging to the family Malvaceae. It only contains one species, Goethalsia meiantha (Donn.Sm.) Burret It is within the Grewioideae tribe.
Description
Goethalsia meiantha is a fast growing, tree reaching to in height. It is buttressed at the base, and has thin bark which whitish or pale, and smooth. The trunk can be up to in diameter and straight. Inside, the trunk is fibrous material, sometimes hanging in strips. The tree branches are coffee-coloured, with numerous whitish lenticules (lens-shaped, porous tissue). Young branches have sparse simple hairs among a dense coat of short fasciculate (in clusters or bunckes) hairs.
The leaves are alternate arranged and ranked along the twigs. They are elliptic-oblong to obovate-oblong shaped. Situated on 10–12 mm long petioles, with small, caducous (falling off early), stipules (small appendage at the bases of leaf). The leaf-blades are long, and wide. The apex of the leaf is narrowly acuminate (tapering gradually to a point), while the base is cuneate (wedge-shaped) to rounded. It has a toothed margin. The upper surface of the leaf, has stellate (star shaped) hairs along the veins. While, the lower surface is off-white in colour, and densely covered with appressed (pressed closely but not fused) stellate hairs. There are 2 to 3 pairs of lateral or major veins, the basal pair of veins, being almost as well developed as the principal vein. The tertiary venation is parallel.
It blooms between June and September, with small yellow, fragrant flowers. The inflorescences are paniculate, both terminal and axillary (arising from the axil) situated. They are shorter than the leaves, and with small (about 2 mm long) persistent bracts. The flowers have an epicalyx (an involucre bract resembling an outer calyx or sepals) of 3 bracteoles (small bracts), which are each 3–4 mm long, and with a pale yellowish pubescence (soft down on the leaves). The calyx and corolla (petals of a flower) are 5-merous. The sepals are lanceolate, shortly connate (cone shaped) at the base, and 10 mm long. They are villous (covered with long, soft, straight hairs), with long simple hairs, on the internal surface, and tomentose (dense covering of short, matted hairs), with fine, stellate, deciduous, hairs, on the outer surface. They are yellow on the inner surface and green on the outer surface. The petals are also yellow. They are oblong or obovate, about 4 mm long and densely villous on the claw of the petal. The remainder of the petal is pappillose (has many small fleshy projections), and is scattered with long stellate hairs. Their base bears long oblong nectarial glands.
The flowers are hermaphroditic, as the stamens and pistils are borne on a short (1.5-1.8 mm long) glabrous (smooth) stalk, or (androgynophore - a stalk bearing both the androecium and gynoecium of a flower). It is surmounted by a villous urceolus (flask-shaped body) which is about 2 mm in diameter, which surrounds the base of the stamens. There are about 25 stamens, in 5 indistinct bundles or groups. they are slightly connate at the base, and have globose anthers. The ovary is sessile (attached without a stalk) on the androgynophore. It has 3 or 4 locules (chambers), each containing 4 ovules. There is a simple, single, filiform (thread-like) style, with an indistinctly 3-lobed stigma.
It fruits from July to January. The fruit (or seed capsule) is composed of 3, or less commonly 2 or 4, connate, indehiscent, samaroid, (similar to a winged seed capsule) mericarps, (one segment of the fruit), which is eventually separate from the central axis. Each fruit is approx. long and wide. They are green when young, maturing to a purplish-grey, or dark green. Each samara is oblong in contour, widely winged around a more or less globular and dark, thicker, central portion, which has an irregular transverse crest. The wings are long and wide. Each samara contains 1 to 4 flattened, pyriform (pear-shaped) seeds, which are 2.8–4 mm long and 1.8-2.5 mm wide. The seed possesses abundant endosperm (tissue around the seed). The cotyledons are flat and leaf-like. Few seeds are viable, because only one of the three joined fruits has an embryo.
Taxonomy
It has the common names of Guácimo blanco, or jaunilama, chancho blanco, guaicimo.
The genus name of Goethalsia is in honour of George Washington Goethals (1858–1928), an American army officer with the United States Army and also Civil engineer. The Latin specific epithet of meiantha is derived from refers to the Greek word meion meaning less, smaller or lesser, and also anther (the pollen-bearing part of a stamen)