Mimosa affinis

Title

Mimosa affinis

Authors

Rupert C. Barneby

Scientific Name

Mimosa affinis B.L.Rob.

Description

389. Mimosa affinis B. L. Robinson, Bot. Gaz. (Crawfordsville) 16: 341. 1891.—".. . in grassy land among cocoanut trees, Mazatlan [Sinaloa, Mexico] and vicinity, January, 1889 ([W. G. Wright] n. 1218 and 1285)." — Syntypi, GH!

M. mazatlana M. E. Jones, Preprinted from Contr. W. Bot. 18: 40. 1933. nom. illeg.—"No. 22451. Mazatlan, Mex. Nov. 20 1928 . .. collected there [actually near Tepic, Nayarit] by Mrs Mexia... Holotypus (Morton, Contr. U.S. Natl. Herb. 29(2): 99.1945), POM 191879 (not seen).—Non M. mazatlana M. E. Jones, 1929.

M. affinis sensu McVaugh, 1987: 201.

Diffuse monocarpic herbs, armed at (and randomly between) nodes, the stems hispid with erect setae to ±1.5-2 mm, the lfts glabrous above, beneath glabrous, minutely puberulent or a few proximal ones also strigose. Stipules 5-7-nerved. Leaf-formula i/8-12, the lf-stks 1.5-3 cm, espiculate, the pinna-rachises 1.5-3.5 cm; lfts oblong ±8-12 x 2—4 mm. Capitula less than 20-fld, at anthesis ±3 mm diam.; bracts linear, setose-ciliate, persistent; flowers with minute glabrous calyces; corolla ±2 mm; filaments exserted ±3 mm. Pods to 10 per capitulum, subsessile, in profile narrowly oblong 10-16 x 4.5-5 mm, abruptly cuspidate, the slender replum hispidulous with weak recurved setulae less than 1 mm, the valves either glabrous or puberulent.

In open grassy places and disturbed brush-woodland, from sea-level to ±950 m in the oak belt, scattered around the Pacific lowlands and in the Balsas depression of Mexico from Sinaloa to Guerrero e. to México and Morelos, s.-e. to Oaxaca; Belize (fide R. Grether).—Fl. VII-I.

This species has been mistaken (as by Isely, 1971: 420) for seedling, conjugate-pinnate M. pudica, but is instantly recognizable by the tiny narrow capitula of ascending flowers.