Hoffmannseggia humilis (M. Martens & Galeotti) Hemsl.

Larrea potosina Britton, sp. nov
Stem only about 6 cm, high. Stipules ovate, acute or acuminate; petioles, rachis and inflorescence loosely pubescent and stipitate-glandular; pinnae 9-13 pairs; leaflets 13-17 pairs, glabrous, nerveless, 2-3 mm, long; raceme several-flowered; pedicels 3-4 mm, long; calyxtube obconic, the lobes narrowly oblong, sparingly pubescent and stipitate-glandular, about 4 mm, long; petals obovate, short-clawed, a little longer than the cahx; legume linear-oblong, about 2 cm. long, 4 mm. wide, obtuse, apiculate, short-appressed-pubescent, sparingly longstipitate-glandular, reticulate-veined.
Dry, calcareous soil, Villar, San Luis Potosi, August 15, 1890, C. G. Pringle 7367.

Larrea platycarpa (Benth.) Britton
Hoffmanseggia platycarpa Benth.; A. Gray. PI. Wright. 1; 57. 1852. Caesalpinia platycarpa E. M. Fisher. Bot. Gaz. 18: 122. 1893.
Stipules ovate, acute; pinnae 8-13; leaflets oblong, nerveless and glandless; calyx-lobes acute, hairy and glandular; petals ovate, scarcely clawed; legume broadly oblong, pubescent, hardly glandular.
Type locauty: Mexico.
Distribution: Known only from the tv-pe locality, and to us from a photograph only.

Larrea pueblana Britton, sp. nov
Stems very short. Stipules ovate-lanceolate, acuminate, pubescent; petioles, rachis and inflorescence short-pilose and stipitate-glandular; pinnae 5-11; leaflets 5-8 pairs, oblong, obtuse, glabrous or ciliate, 5-8 mm. long, minutely subpapillose; pedumcle about as long as the leaves, or shorter; raceme few-flowered; pedicels 4-6 mm. long, stipitate-glandular; calyx pilose and stipitate-glandular, its lobes about 4 mm. long; petals about 5 mm. long; legume linear, straight, about 2 cm. long, 4—6 mm. wide, short-puljescent and strongly reticulate-veined, nearly eglandular.
Cerro de Coatepe, Puebla, near Oaxaca, August 1908, C. A. Pur pus 3220.

Larrea humilis (ISIart. & Gal.) Britton
Pomaria humilis Mart. & Gal. Bull. Acad. Brux. 10=: 303. 1843. Hoffmanseggia humilis Hemsl. Biol. Centr. Am. Bot. 1: 326. 1880.
A low shrub. Stipules ovate-lanceolate, acuminate, entire; petioles, peduncle and calyx glandular-pilose; leaflets about 6 pairs, elliptic, mucronulate, pilose beneath; raceme axillary, many-flowered, a little shorter than the leaves, the flowers and fruit deflexed; legume ovalelliptic, flat, pilose, apiculate.
Type locality: Calcareous mountains north of Tehuacan, Puebla.
Distribution: Known only from the type locality and to us from description only.

Larrea gladiata (Benth.) Britton
Hoffmanseggia gladiata Benth.; A. Gray, PI. Wright. 1; 57. 1852. Caesalpinia gladiata E. M. Fisher, Bot. Gaz. 18: 122. 1893.
Stipules ovate, acute; pinnae 7-13; leaflets oblong, without nerves or glands; calyxlobes acute, hirsute and glandular; petals oblong, with very short claws; legume lanceolate, slightly incurved, hirtellous and sparingly glandular.
Type locality: Zimiapan, Hidalgo.
Distribution: Known only from the type locality, and to us from a photograph only.

Hoffmannseggia humilis là một loài thực vật có hoa trong họ Đậu. Loài này được (M.Martens & Galeotti) Hemsl. miêu tả khoa học đầu tiên.