Mimosa myriadenia var. dispersa 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 myriadenia var. dispersa Barneby

  • Type

    1d. Mimosa myriadenia (Bentham) Bentham var. dispersa Barneby, var. nov., foliorum formula foliolorumque ambitu inter varietates myriadeniam et egenam interludens, cum ilia pinnarum numero congrua sed foliolis confertis (inter se contiguis vel imbricatis

  • Description

    Variety Description - Leafstalks of longer lvs 7-14 cm, the petiole 0.7-2.2 cm, the longer interpinnal segments 5 9 mm; pinnae of longer lvs 11-16-jug., the rachis of longer ones 3-6.5 cm, the interfoliolar segments 0.4-1.4 mm; lfts of longer pinnae 24-42- jug., linear-oblong acute, to 3.5-6.5 x 0.6-1.4 mm, 4-6 times as long as wide, 1-3-nerved from pulvinule, the midrib a little displaced, the posterior nerve(s) short and faint.

    Distribution and Ecology - In the riparian and forest habitats of var. myriadenia and discontinuously dispersed within its range: interior Surinam (Wilhelmina Mts.) and adj. Pará, Brazil (Sa. Tumucumaque); río Negro-Orinoco divide in Amazonas, Brazil and T. F. Amazonas, Venezuela; Pacific and n. inter-Andean Colombia; near 300 m in sub-Andean Ecuador (Napo) and Peru (Amazonas, Huanuco). — FI. X-III(-V). Map 1.

  • Discussion

    The discontinuous known range of var. dispersa, partly within and partly to the west of var. myriadenia, could be explained in two ways, neither ostensibly the more probable. The variety may be of polyphyletic origin and consist of historically independent but parallel modifications derived from var. myriadenia. Or alternatively, the dispersed populations represent a primitive stock from which the other varieties of M. myriadenia have issued, var. egena by multiplication of smaller leaflets and vars. myriadenia and punctulata by progressive amplification and loss of number.

  • Distribution

    Peru South America| Amazonas Peru South America| Huánuco Peru South America| Ecuador South America| Napo Ecuador South America| Colombia South America| Venezuela South America| Amazonas Venezuela South America| Brazil South America| Pará Brazil South America| Amazonas Brazil South America|