Mimosa quadrivalvis var. angustata

  • Title

    Mimosa quadrivalvis var. angustata

  • Authors

    Rupert C. Barneby

  • Scientific Name

    Mimosa quadrivalvis var. angustata (Torr. & A.Gray) Barneby

  • Description

    190h. Mimosa quadrivalvis Linnaeus var. angustata (Torrey & Gray) Barneby, comb. nov., based on autonym generated by Schrankia angustata var. brachycarpa Chapman, 1865, q.v. infra. S. angustata Torrey & Gray, Fl. N. Amer. 1:400. 1840.—"S. uncinata [sensu] Elliott. Sk. 2 p. 158 (at least in part, ex spec.!)... S. Carolina! Georgia! Texas, Drummond!"—Lectotypus, Drummond s.n., NY (hb. Torrey.!), the only fruiting specimen that could have suggested the epithet, which refers to the legume "subulate-attenuate at the apex"; syntypus, Elliott s.n. (fl), NY (hb. Torrey.!).

    M. microphylla Dryander in J. E. Smith, Nat. hist. lepidopt. Georgia 2: 123. 1787.—No locality given other than Georgia, in the book-title.—Holotypus, the plate at page cited! = var. angustata sens. lat., but the pod not shown, the particular variant therefore unknowable.— Morongia microphylla (Dryander) Britton in Britton & Brown, I11. Fl. n. U.S., ed. 2, 2: 334. 1913. Leptoglottis microphylla (Dryander) Britton & Rose, N. Amer. Fl. 23(3): 142. 1928.

    M. horridula Michaux, Fl. bor.-amer. 2: 1803. —"HAB. a Virginia ad Floridam."—Holotypus, P (hb. Michaux.)! = photo s.n. ex ISC, showing dorsal face of lfts in enlargement, NY! = the variant with shorter, densely aculeate pod .—Schrankia uncinata Willdenow, Sp. pl. 4: 1043. 1806, nom. illeg. S. horridula (Michaux) Chapman, Fl. South. U.S. ed. 2, 683. 1892. Morongia uncinata (Willdenow) Britton, Mem. Torrey Bot. Club 5: 191. 1894, nom. illeg. Morongia horridula (Michaux) A. Heller, Cat. N. Amer. pl. 5. 1898.

    Schrankia angustata ? var. brachycarpa Chapman, Fl. South. U.S. 116. 1865.—"Dry pine barrens, Florida to North Carolina, and westward."—Two sheets from hb. Chapman., so identified in Chapman’s hand, one from "Florida," NY! = the variant with shorter, more densely aculeate pod, the same as the preceding.— Leptoglottis chapmanii Small ex Britton & Rose, N. Amer. Fl. 23(3): 141. 1928. Schrankia chapmani [sic] (Small) F. J. Hermann, J. Wash. Acad. Sci. 38: 237. 1948.

    S. horridula var. ? angularis Chapman, Fl. South. U.S. ed. 3, 127. 1897.—"Dry open woods in the upper districts."—Lectotypus (Isely, 1971a: 239): Chapman s.n., "near Rome, Georgia . . .," US! = the variant with relatively long, more distantly aculeate pod.— Morongia horridula var. angularis (Chapman) A. Heller, Cat. N. Amer. pl. 5. 1898. Leptoglottis halliana Britton & Rose, N. Amer. Fl. 23(3): 141. 1928.—"Sandy hills, Hemstead [Waller Co.], Texas, June 1, 1912, Elihu Hall 171"—Holotypus, NY! = the form with long slender, sparsely aculeate pod equivalent to typical var. angustata', isotypus, K! L. angustisiliqua Britton & Rose, N. Amer. Fl. 23(3): 143. 1928.—"Type from Brogdon Hammock, Dade County, Florida, June 19, 1915, [J. K.] Small & [C. A.] Mosier 6349."—Holotypus, NY! = the variant with exceptionally narrow, distantly aculeolate pod found in s. peninsular Florida .—Schrankia angustisiliqua (Britton & Rose) F. J. Hermann, J. Wash. Acad. Sci. 38: 237. 1948.

    Leaf-formula (iii-)iv-viii/(9-) 10— 17(— 19); longer lf-stks (6—)7—15 cm, the petiole (1.5-)2-4 cm, shorter than rachis; rachis of longer pinnae (10-)14-42 mm; longer lfts 2.5-7.5 x 0.6-1.7 mm, the venation immersed, either discolored or imperceptible dorsally; peduncles 2-6 cm; capitula without filaments 5-7.5 mm diam.; pod polymorphic in dimensions and armature, either a) elongate, 8-13 cm with long sterile beak, discounting prickles 3-4.5 mm diam., or b) of similar length but only (2-)2.5-3 mm diam., or c) only 4-8 cm long, often more shortly beaked and more densely prickly with basally confluent aculei, the replum (2-)2.2-3.5 mm and the valves (1.7-)2-2.5 mm wide, the whole either glabrous or puberulent; seeds 14-20(-24).

    In open sunny places on sandy or loamy soils of pine-palmetto savanna and mixed deciduous woodland of the coastal plain and piedmont, becoming weedy in fallow ground, along highways, and in waste places, widespread and frequent from far w. Virginia and s.-e. Kentucky to s. peninsular Florida, s.-w. to s. Louisiana and e. Texas (Isely, 1973, map 46, sub Schrankia microphylla, but this excluding the Texan populations shown by Turner, 1939: 46, map 16).—Fl. IV-X, into winter in subtropical Florida.

    Except for nomenclature, contingent on the taxonomy, my concept of var. angustata coincides with Schrankia microphylla sensu Isely (1971a, 1973) except in this respect: I follow Turner (1959) by including Leptoglottis halliana, the lectotype of Schrankia angustata, and similar east-Texan schrankias with leaf-formula of iii— vi/12-18 and long narrow pods, which appear to me indistinguishable from some populations in Florida. These controversial taxa were transferred by Isely to Schrankia latidens, but contradict the contrasting morphological definitions presented in his key and discussion (1971a: 234, 236). There appears to be a narrow gap in the known dispersal of var. angustata in Louisiana between the lower Mississippi and lower Sabine rivers, but this gap cannot outweigh morphological congruence between plants found to the east and west.

    The variation in length and armature of the fruit of var. angustata was noted by Chapman, and has given rise to a number of proposed segregates; these, however, as Isely has ably demonstrated, lack geographic patterns, except insofar as the state with short, usually burrlike but sometimes only thinly aculeate pod, is not encountered at the southern and western extremities of the dispersal range. No significant correlation has been found between length, girth, pubescence, and armature of fruit, which vary independently of one another. Occasional plants in Florida have incipiently elevated midrib on back of leaflets, suggesting passage into var. floridana.