Systematics Section / ASPT
Barnes, Donna M. , Johnson, Leigh A. .
Reappraised pollen morphology and sectional classification in Navarretia (Polemoniaceae).
Pollen morphology of all species and sub-species of Navarretia (Polemoniaceae) was examined by scanning electron microscopy. Seven distinct pollen types with 1-5 sub-types were observed. Type determinations were based primarily on surface sculpturing: Type I - semitectate, heterobrochate, reticulate; Type II - semitectate, reticulate, heterobrochate, echinate, with flattened, cross etched muri; Type III - semitectate, finely striate; type IV - semitectate, striate-reticulate; Type V - semitectate, microreticulate, heterobrochate, microechinate; Type VI - semitectate, rugulose; Type VII - tectate, perforate, microechinate. Evaluation of pollen morphology revealed discrepancies with regard to previously described Navarretia pollen grains, and in respect to accepted sectional classifications. Discrepancies in pollen morphology include the following: 1) Stuchlik's (1967) description of N. leucocephala, N. minima (N. leucocephala subsp. minima) and N. prostrata as having a retipilate sexine and N. prolifera as having a reticulate sexine with uniform lumina; 2) Taylor and Levine's (1975) description of N. plieantha (N. leucocephala subsp. plieantha) as having a foveolate sexine, N. atractyloides as having a striato-reticulate sexine and N. prolifera subsp. lutea as having a finely reticulate sexine with elongate lumina; and 3) Grant and Day's (1998) description of Gilia capillaris (N. capillaris) and G. leptalea subsp. bicolor (N. leptalea subsp. bicolor) as having a striate sexine and G. sinistra subsp. sinstra (N. sinistra) as having a pertectate sexine. Sectional discrepancies are as follows: Type I includes taxa from sections Masonia, Mitracarpium, and Navarretia. Type II generally corresponds with section Navarretia. Types III and IV include taxa from sections Masonia and Ageochloa. Types V and VI include taxa from section Ageochloa. Type VII includes taxa new to Navarretia, in which the section has not yet been specified.
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1 - Brigham Young University, Department of Integrative Biology, P.O. Box 5181, Provo, Utah, 84602, USA
Navarretia sectional classification.
Presentation Type: Oral Paper
Date: Monday, August 15th, 2005
Time: 4:15 PM