Machaonia portoricensis Baill.

Machaonia portoricensis Baillon, Bull. Soc. Linn. Paris 1: 204
1879. A densely branched shrub or small tree, 2-6 meters high, the branches dark-brown, coarsely lenticellate, armed with numerous stout or slender, opposite or ternate spines, the branchlets reddish-brown, puberulent in lines; stipules minute, cuspidate; leaves mostly ternate, the petioles 2 mm. long or shorter, puberulent, the blades orbicular, rhombic-orbicular, oval, or rhombic-ovate, 7-15 mm. long, 5-12 mm. wide, sometimes broader than long, rounded to obtuse at the base, rounded to acute at the apex, usually broadly and acutely short-acuminate, membranaceous or chartaceous, glabrous, slightly paler beneath, the lateral nerves subimpressed, 2 or 3 on each side, the venation reticulate; inflorescence fewor many-flowered, 1-3.5 cm. wide, usually dense, the flowers sessile or short-pedicellate, the bracts often large and foliaceous; calyx and hypanthium 2-3 mm. long, densely short-pilose, the hypanthium turbinate, the 4 calyx-lobes oblong, obtuse or acute, about as long as the hypanthium, much shorter than the fruit; corolla white, 3-3.5 mm. long, glabrous outside, the lobes oval, half as long as the tube; anthers exserted; fruit turbinate, 3 mm. long, densely short-pilose.
Type locality: Puerto Rico.
Distribution: Rocky woods and thickets at lower elevations, western and southwestern Puerto Rico.

Machaonia portoricensis là một loài thực vật có hoa trong họ Thiến thảo. Loài này được Baill. mô tả khoa học đầu tiên năm 1879.