DARWINIANA
34(1-4): 19-26. 1996
NECTARIOS Y TRICOMAS FLORALES EN CUATRO ESPECIES
DE TECOMEAE (BIGNONIACEAE)
GUILLERMO RIVERA
Instituto Multidisciplinario de Biología Vegetal (IMBIV),
C.C. 495, 5000 Córdoba, Argentina
ABSTRACT: Rivera, G. L. 1996. Floral trichomes and nectaries in four
species of Tecomeae (Bignoniaceae). Darwiniana 34: 19-26.
The structure and anatomy of floral trichomes and nectaries of 4 species
of Tecomeae (Bignoniaceae) are studied. All taxa exhibit pluricellular
glandular trichomes of different forms and distribution in calyx, corolla
and ovary wall and bear a conspicuous floral nectary except for Catalpa
bignonioides Walter. In this species the floral nectary is reduced
and appears to be a vestigial organ without a secretory function. The nectary
of Argylia radiata (L.) D. Don, Podranea ricasoliana (Tanfani)
Sprague and Pandorea jasminoides (Lindl.) K. Schum. comprises epidermis
and secretory parenchyma without intercellular spaces. Secretory tissue
is supplied by phloem. Raised nectarial stomata were found only in P.
ricasoliana, whereas they are at the same level of the epidermis in
the remainder species. Extrafloral nectaries were found in flowers of P.
jasminoides and P. ricasoliana in the outer surface of the calyx.
Those of P. jasminoides are cupular and vascularized while those
of P. ricasoliana are patelliform and
nonvascularized.