Mimosa domingensis

  • Title

    Mimosa domingensis

  • Author(s)

    Rupert C. Barneby

  • Scientific Name

    Mimosa domingensis (Bertero ex DC.) Benth.

  • Description

    108. Mimosa domingensis (DeCandolle) Bentham, J. Bot. (Hooker) 4: 409. 1842, based on Acacia domingensis DeCandolle, Prodr. 2:464. 1825.—"in Sancto-Domingo. (Bertero . . . v.s. comm. a cl. Balbis.)"—Holotypus, G-DC! = F Neg. 33450.

    M. mornicola Urban, Symb. antill. 7: 228. 1912.— "Hab. in Haiti in Mome Bonpère [probably Morne Bobère, ± 12 km n.-e. from Gros Mome in the Chaîne de Plaisance . .. 600 m alt., m. Jun. [1901] flor.: Buchn. 685."—Holotypus, +B; isotypi, GH! IJ!; photo + fragments, NY! US (misit Urban 26.VII.1926)! M. buchii Urban, Repert. Spec. Nov. Regni Veg. 22: 89. 1925.—"Hab. in Haiti septentrionali prope Moustique . . . 250 m alt., m. Jul. flor.: Buch no. 2116."—Holotypus, +B; isotypus, IJ!

    M. farisii Leonard ex Britton & Rose, N. Amer. Fl. 23: 164. 1928.—"Nigua, Santo Domingo, July, 1921, James A. Faris 447."—Holotypus, US!; clastotypus, NY!—Equated by Rose & Leonard, 1927, with H. mornicola.

    M. azuensis Britton ex Britton & Rose, N. Amer. Fl. 23: 164. 1928.—"Azua, Santo Domingo, March 17, 1913, Rose, Fitch & Russell 3994.’’—Holotypus, NY!; isotypus, US!—Equated by Rose & Leonard, 1927, with M. mornicola.

    Acacia tamarindifolia sensu Grisebach, Cat. pl. Cub. 82. 1866; non Willdenow. Mimosa polyancistra sensu Bentham, 1875: 422.—"Cultivated in Mr. Chapy’s garden at Havannah from the West Indies, M’Lane[382, K!]"-Non M. polyancistra Bentham, l.c., vera (Pavoniana).

    Mimosa domingensis sensu Bentham, 1875: 424.

    M. mornicola sensu Britton & Rose, 1928: 152; Rose & Leonard, 1927: 258; Liogier, 1985: 51.

    M buchii sensu Britton & Rose, 1928: 152; Liogier, 1985: 48.

    M. azuensis sensu Liogier, 1985: 48.

    M. farisii sensu Liogier, 1985: 50.

    Scrambling shrubs 2-10 m, sarmentose in closed brush or woodland communities but when lacking support forming impenetrable tangles, commonly armed randomly on stems at and sometimes also below nodes, on lf-stks immediately below insertion of some or all pairs of pinnae, and commonly at tip of all or many pinna-rachises with vulnerant recurved dark-tipped aculei 0.5-2 mm, but in some samples the aculei few or lacking, the fuscous striped homotinous stems, lf-axes and peduncles minutely puberulent and microscopically livid-granular, the bicolored lfts glabrous dark green sublustrous above, paler dull beneath, the subglobose or ovoid capitula 1-3-nate in axils of primary lvs or, in praefloration or early anthesis, shortly pseudoracemose at end of hysteranthously leafy branchlets. Stipules erect or (when long) incurved-ascending, narrowly subulate or linear-setiform 16 x 0.2-0.6 mm, tardily deciduous. Leaf-stalks of primary lvs 3.5-8.5(-10) cm, the petiole including livid pulvinus (4—)5— 12(— 16) x 0.6-1.2 mm, the longer interpinnal segments (5-)6-10 (-14) mm, the ventral groove continuous or obscurely bridged between pinnae but spicules 0; pinnae of primary lvs 5—10(—1 l)-jug., of occasional lvs on secondary branchlets fewer (no further described), subequilong or subdecrescent at one or both ends of lf-stk, the forwardly curved rachis 12-25(-37) mm, the longer interfoliolar segments 1.5-4(-6) mm; lfts of longer pinnae 56 (in Nord-Ouest, Artibonite), 7-9 (in San Cristóbal, Azua) or -11-jug. (in Espaillat), a little decrescent proximally, the first pair 0.7-2.5 mm distant from ascending subulate paraphyllidia 0.1-0.5 mm, the plane or ventrally subconvex blades varying from narrowly oblong or oblong-elliptic to elliptic-obovate from shallowly semicordate or obliquely obtusangulate base, broadly rounded or subemarginate at apex, the longer ones 5-8.5 x (1.8-)2-3.5(-5) mm, (1.6-)2-3 times as long as wide, all almost imperceptibly veined above, beneath weakly finely 2-4-nerved from pulvinule, the scarcely displaced midrib faintly 1-3-branched on each side, the anterior (sometimes wanting) and inner posterior nerves weakly anastomatizing beyond mid-blade. Peduncles 6-18, rarely 25-30 mm; capitula without filaments ±(3.5-)4-6 mm diam., prior to anthesis moriform, the narrowly claviform receptacle 2.5-4.5 mm long; bracts minute puberulent, caducous; flowers whitish, 4-5-merous 4-10-androus; calyx campanulate, externally puberulent, 0.7-1.1 mm, the deltate teeth 0.1-0.15 mm; corolla vaseshaped 1.9-4.1 mm, the 1-nerved lobes 0.8-1.2 x 0.6-0.8 mm; filaments either free or obscurely connate at very base, exserted 2-5 mm. Pods 1-3 per capitulum, subsessile or narrowed at base into a stipe to 3 mm, the body in profile broadly linear, falcately incurved 35-50 x 7-9(-10) mm, 6-8-seeded, the unarmed, shallowly constricted replum 0.3-0.5 mm wide, produced as an erect terminal cusp 3-5 mm, the papery reddish-brown or ultimately fuscous, microscopically puberulent and weakly venulose valves breaking up when ripe into free-falling indehiscent articles 5.5-8 mm long; seeds plumply discoid 3.3-4.2 mm diam., the smooth brown testa sublustrous.

    In xeromorphic scrub and woodland, on limestone and sometimes on serpentine, mostly between sea-level and 300 m but attaining 700(-?) m in n.-w. Haiti, scattered over Hispaniola from dep. Nord-Ouest s. to dep. Ouest in Haiti and e. in Dominican Republic to deptos. Espaillat and San Cristóbal.-Fl. II-IV, VII-IX, probably in other months.

    Mimosa domingensis is the coarse trailing or sarmentose member and M. diplacantha the dwarf or bushy microphyllidious member of a closely related pair of species endemic to Hispaniola, the names of which have long been confused. The identity of the first is known from the surviving holotypus of Acacia domingensis DC. The holotypus of M. diplacantha, now destroyed, was available to Urban at Berlin in his studies of Antillean Mimosa, and at one point (1920: 259) he explicitly associated it with Rose & al. 4018 from Azua, a specimen of the dwarf species. Taking into account Urban’s powers of minute observation I regard this as powerful indirect proof of the identity of M. diplacantha, borne out, furthermore, by the protologue. Urban, however, identified this material as M. domingensis. In consequence, the true M. domingensis, as new collections from Hispaniola reached Urban in Berlin and Britton in New York, was naturally thought to be undescribed. Its unarmed or weakly armed states were distinguished as M. mornicola by Urban and as M. azuensis by Britton & Rose, and the strongly armed state as M. buchii by Urban and as M. farisii by Britton & Rose.

    A peculiar feature of both M. domingensis and M. diplacantha is the variable number of stamens, the 4-5-merous flowers varying from fully diplostemonous to exactly haplostemonous, but most falling somewhere between the two. Mimosa mornicola and M. buchii, which Urban had described as having four or five stamens per flower, were for this reason narrowly interpreted by Britton & Rose as members of sect. Eu-mimosa and transferred from their natural position next to M. fagaracantha in sect. Habbasia to a specially provided ser. Mornicolae in sect. Eu-mimosa.

    I am indebted to Dr. T. Zanoni for identifying Buch’s "Mome Bonpere" in Haiti, type-locality of M. mornicola.

    The isotype of M. buchii that survives at Kingston, Jamaica is now somewhat fragmentary but seems to consist of the tips of flowering branches and consequently does not show any primary stem leaves. The largest leaves on the specimen have four pairs of pinnae, which suggests M. leonardii, but the leaf-stalk is not dilated as in that species.