Skip Navigation



AOBPreview published online on August 7, 2007
Annals of Botany, doi:10.1093/aob/mcm165
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow All Versions of this Article:
100/4/797    most recent
mcm165v1
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Google Scholar
Right arrow Articles by Davies, K. L.
Right arrow Articles by Stpiczynska, M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Davies, K. L.
Right arrow Articles by Stpiczynska, M.
Agricola
Right arrow Articles by Davies, K. L.
Right arrow Articles by Stpiczynska, M.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© The Author 2007. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oxfordjournals.org

Micromorphology of the Labellum and Floral Spur of Cryptocentrum Benth. and Sepalosaccus Schltr. (Maxillariinae: Orchidaceae)

Kevin L. Davies1,* and Malgorzata Stpiczynska2

1 School of Earth, Ocean and Planetary Sciences, Cardiff University, Main Building, Park Place, Cardiff CF10 3YE, UK
2 Department of Botany, Agricultural University, Akademicka 15, 20-950 Lublin, Poland

* For correspondence. E-mail kevinldavies{at}btinternet.com

Received: 16 April 2007    Returned for revision: 29 May 2007    Accepted: 14 June 2007   

Background and Aims: Gross vegetative and floral morphology, as well as modern molecular techniques, indicate that Cryptocentrum Benth. and Sepalosaccus Schltr. are related to Maxillaria Ruiz & Pav. However, they differ from Maxillaria in their possession of floral spurs and, in this respect, are atypical of Maxillariinae. The labellar micromorphology of Maxillaria, unlike that of the other two genera, has been extensively studied. In the present report, the labellar micromorphology of Cryptocentrum and Sepalosaccus is compared with that of Maxillaria and, for the first time, the micromorphology of the floral spur as found in Maxillariinae is described.

Methods: Labella and dissected floral spurs of Cryptocentrum and Sepalosaccus were examined using light microscopy (LM) and scanning electron microscopy (SEM).

Key Results: In each case, the labellum consists of a papillose mid-lobe (epichile), a cymbiform region (hypochile) and, proximally, a spur, which is pronounced in Cryptocentrum but short and blunt in Sepalosaccus. The inner epidermal surface of the spur of Cryptocentrum is glabrous or pubescent, and the bicellular hairs, where present, are unlike any hitherto described for Maxillariinae. Similar but unicellular hairs also occur in the floral spur of Sepalosaccus, whereas the glabrous epidermis lining the spur of C. peruvianum contains putative nectar pores.

Conclusions: The labellar micromorphology of Cryptocentrum and Sepalosaccus generally resembles that of Maxillaria. The floral spur of Cryptocentrum displays two types of organization in that the epidermal lining may be glabrous (possibly with nectar pores) or pubescent. This may have taxonomic significance and perhaps reflects physiological differences relating to nectar secretion. The trichomes found within the spurs of Cryptocentrum and Sepalosaccus more closely resemble the hairs of certain unrelated, nectariferous orchid taxa than those found in the largely nectarless genus Maxillaria, and this further supports the case for parallelism.

Key words: Labellum, Maxillariinae, micromorphology, nectar pore, nectary, spur, trichome


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer:
Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.