Scleria bracteata Cav.

  • Authority

    Koyama, Tetsuo M. 1967. The systematic significance of leaf structure in the tribe Sclerieae (Cyperaceae). Mem. New York Bot. Gard. 16: 46-70.

  • Family

    Cyperaceae

  • Scientific Name

    Scleria bracteata Cav.

  • Description

    Species Description - Leaf blades inversely W-shaped with broad wings; principal costas 5. Leaf blade proper. Inflated epidermal cells at median adaxial groove ovate-orbicular or nearly cubic, 1-layered. Cells of the rest of adaxial epidermis and whole abaxial epidermis small, uniformly square; a few epidermal cells protruding into long unicellular hairs. Mesophyll differentiated into palisade and spongy portions; palisade chlorenchyma mostly 2-layered; spongy chlorenchyma with intercellular spaces between vascular bundles, the component cells loosely oriented, lobed or stellate. Rather small number of tannin cells in spongy mesophyll. Vascular bundles arranged in a single row in middle spongy mesophyll; bundle sheaths double, the inner bundle sheath lignified, cells of the outer bundle sheath thin-walled, slightly larger than those of the inner sheath. Almost all vascular bundles supported by an adaxial and an abaxial low girder, some small bundles with an abaxial girder only. Wings. Abaxial epidermis outside the adnated portion inflated, the component cells tall, longitudinally rectangular or almost cubic. The rest of epidermis with small cells. Mesophyll structurally the same as that of the leaf blade proper. A pair of large and small vascular bundles noted in the adnated area of each side; large vascular bundle vertical, with well-developed adaxial and abaxial girders; subjoining small vascular bundle oblique, adaxially supported by a low girder. Larger vascular bundles inversed, the small ones oblique, both kinds with adaxial or abaxial sclerenchyma or both.

  • Discussion

    Note. The structure closely resembles that of Scleria abortiva described and illustrated by Chermezon (1926), especially in the unusual orientation of the vascular bundles in wings. Larger vascular bundles in wings are oriented with their phloem facing the adaxial epidermis, a condition usually found in the stem bundles. This inversion in arrangement does not occur in the assimilatory tissues of mesophyll.