Developmental and Structural Section
Lersten, Nels R. , Horner, Harry T. .
Analysis of leaf crystal variations and macropatterns in Oleaceae.
The Oleaceae (Lamiales) has 25 genera and 600 species of trees, shrubs and woody vines distributed in five tribes that occur on all continents except Antarctica. Crystal macropatterns (types of crystals and their specific cell and tissue distribution in a leaf) have not been described in the Oleaceae. The four earlier references that mention crystals in Oleaceae leaves all indicate that some unusual crystal forms occur. The Oleaceae leaves surveyed from herbarium specimens of 240 species from 23 genera were rehydrated, bleached, processed into xylol, mounted unstained, and viewed microscopically between crossed polarizers. Occurrence of five crystal types and two variants (slivers and sphaerites) within one family is unusual. The number of crystal types within a single species was one (108 sps.), two (53 sps.), three (51 sps.), four (15 sps.), and five (6 sps.). Seven species lacked crystals. The ‘sliver’ variant was most common (167 sps.), followed by prisms (67 sps.), raphides (65 sps.), druses (61 sps.), sphaerites variant (50 sps.), styloids (36 sps.) and crystal sand (21 sps.). Epidermal crystals were common (155 sps.), with some crystals clustered at the bases of trichomes in 21 species. Jasminum was exceptional in having mostly druses and almost no crystals around vascular bundles. Most Oleaceae crystals are tiny, about five micrometers in diameter or length, except for larger styloids and raphides. In several Oleaceae species, crystals only occur in the epidermis, while in other species crystals occur only in the epidermis and along vascular bundles, with none in the mesophyll. Also unusual is the absence of foliar crystals in parenchyma or sclerenchyma fibers within major vascular bundles of all species examined; all bundle-associated crystals occur only along their periphery. This survey has expanded greatly on earlier work to show that crystallization has evolved within the Oleaceae in unusual and diverse directions.
Log in to add this item to your schedule
1 - Iowa State University, Ecology, Evolution and Organismal Biology, 253 Bessey Hall, Ames, IA, 50011, USA
2 - Iowa State University, Genetics, Development and Cell Biology & Microscopy and NanoImaging Facility, Ames, IA, 50011-1020, USA
Presentation Type: Oral Paper:Papers for BSA Sections
Location: Ballroom 3/Cliff Lodge - Level B
Date: Monday, July 27th, 2009
Time: 2:30 PM