Monographs Details: Mimosa deceptrix Barneby
Authors:Rupert C. Barneby
Authority: Barneby, Rupert C. 1991. Sensitivae Censitae. A description of the genus Mimosa Linnaeus (Mimosaceae) in the New World. Mem. New York Bot. Gard. 65: 1-835.
Family:Mimosaceae
Scientific Name:Mimosa deceptrix Barneby
Synonyms:Mimosa regnellii Benth.
Description:Species Description - Virgately erect, unarmed shrubs or subshrubs ±9-15 dm, the commonly simple stiff striate reddish-brown stems bearing below middle a few amply microphyllidious lvs sometimes subtending inhibited lateral branchlets and passing upward into a simple or few-branched, leafless multicapitulate pseudoraceme rising 5-8 dm beyond the last lf, the stems below middle either strigose or hispid with appressed or spreading-ascending, microscopically papillose-puberulent, tapering setae to 2-3.5 mm, distally like lf-stks and axis of pseudoracemes strigose with shorter subappressed setae often mixed with fine puberulence, the foliage when dry dull brown-olivaceous, the concolorous lfts microscopically puberulent facially, weakly setose-ciliolate. Stipules linear-lance-attenuate 4-8 x 0.4-0.9 mm, 1-nerved distally, setose dorsally, persistent. Leaf-stalks of primary lvs (7.5-)9-16 cm, the petiole including hard pulvinus 0.8-2.5 cm, at middle 0.7-1.4 mm diam., the interpinnal segments 7-12 mm, the ventral groove obscure, interpinnal spicules 0; pinnae (9-) 12-16-jug., subequilong or a little decrescent at either end of lf-stk, the rachis of longer ones 3-5.2 cm, the interfoliolar segments 0.7-1.4 mm; lfts of longer pinnae (26-)30-46-jug., subequilong except at very ends of rachis, the first pair 0.3-0.5 mm distant from subulate-subsetiform paraphyllidia almost concealed in setae, the blades narrowly oblong from semicordate base, acute or mucronate at apex, those at and near mid-rachis 3.5-5 x 0.9-1.3 mm, 3-5(-5.5) times as long as wide, all veinless on upper face, beneath pallidly 1- or 3-nerved from pulvinule, the midrib subcentric, simple or beyond middle weakly 1 (-2)-branched, the branches incurved and anastomosing with the weak primary nerve on each side. Peduncles (1—)2—3 per node, at anthesis 8-14 mm; capitula subglobose, without filaments 5-6.5 mm diam., prior to anthesis moriform, the fl-buds gray-puberulent at tip; receptacle setose; bracts narrowly linear-oblanceolate 1.7-2.4 x 0.2-0.3 mm, subscarious, distally brownish and minutely or weakly ciliolate; flowers 4-merous 4-androus, most or all bisexual; calyx paleaceous-pappiform 1.6-2 mm, the lobes decompound nearly to base into lustrous setae; corolla subcylindric 2.2-2.8 mm, the ovate concave, scarcely callous lobes 0.6-0.8 x 0.3-0.4 mm; filaments lilac-pink, free to base, exserted 5-6 mm; anthers 0.25-0.3 mm diam.; ovary at anthesis glabrous; style about as long as filaments; pod unknown.

Distribution and Ecology - In campo near 850-950 m, apparently local about the sources of rio Iguaçu w. and s.-w. of Curitiba, Paraná (Campo Largo; S. José dos Pinhaes; Quatro Barras; Araucária; Serrinha).—Fl. XI-II.

Discussion:

This handsome campo mimosa, which was perceived by Per Dusén to be allied to but (in herbarium notation) different from M. regnellii, was mistaken by Burkart for that species. It differs from var. regnellii in virgate habit, with few large leaves below mid-stem and an extremely long efoliate and multicapitulate pseudoraceme, branched or not, overtopping the foliage by 5-8 dm, and further by concolorous, symmetrically linear-oblong leaflets with a centric costa either solitary or accompanied on each side by a narrowly intramarginal nerve. In the asymmetrically costate leaflets of M. regnellii the midrib is accompanied on the posterior side alone by primary nerves and the margin of the leaflets is rimmed with pallid tissue. The habit of M. regnellii, when all varieties are considered, is somewhat diverse, but the mature plants are usually distinctly fruticose, with defoliate trunks and densely leafy homotinous branches. The varieties of M. regnellii sympatric or nearly so with M. deceptrix in eastern Paraná differ further in short leaves and few pinnae.

Distribution:Brazil South America| Paraná Brazil South America|

Narratives:Mimosa deceptrix