Stipular extranuptial nectaries new to Polygala: morphology and ontogeny

Author(s)

Andrade De Aguiar-Dias, Ana Cristina ^[1] ; Yamamoto, Kikyo ^[2] ; Castro, Marilia De Moraes ^[2]

Affiliation

^[1] Univ Estadual Campinas, Inst Biol, BR-13083970 Campinas, SP - Brazil

^[2] Univ Estadual Campinas, Dept Biol Vegetal, Inst Biol, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: Botanical Journal of the Linnean Society; v. 166, n. 1, p. 40-50, MAY 2011.
• Web of Science Citations: 4

Abstract

Although taxonomic studies indicate that approximately one-third of the genera of Polygalaceae have nodal glands, few anatomical data are available on the structure and ontogeny of these secretory organs. We studied the as yet unknown origin, structure and function of such glands in Polygala laureola. During field observations, we detected glucose in the secretion using Glicofita Plus (R) and visitors were recorded. Vegetative shoot apices and nodal glands were examined using light microscopy and scanning electron microscopy. The presence of glucose in the secretion allowed us to identify these nodal glands as extranuptial nectaries. Secretory cells occupy a medullary position and are surrounded by phloem. Vascular bundles are concentric, and xylem is only observed at the basal region of the nectary. Nectar is released during the daytime through a pore at the top of the nectary. A stipular origin was confirmed by the fact that the procambial strand is connected to the leaf trace, opposite the leaf gap. The occurrence of stipular extranuptial nectaries in a nodal position is new to Polygala. (C) 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 166, 40-50. (AU)

• FAPESP's process: 03/12595-7 - Floristic composition, structure and functioning of the Dense Rainforest nuclei of Picinguaba and Santa Virgínia of Parque Estadual da Serra do Mar, State of São Paulo, Brazil
• Grantee: Carlos Alfredo Joly
• Support Opportunities: BIOTA-FAPESP Program - Thematic Grants