Abstract
The diversity of crystal types is studied in fruiting calyces of 435 out of the c. 7,200 species, and 184 out of the c. 236 genera of Lamiaceae, mainly in the subfamilies Nepetoideae and Lamioideae. Calcium oxalate crystals are found in about half of the studied calyces, and belong to the following main types: prismatics in the inner epidermis, prismatics in fibres, prismatics in sclereids, prismatics in the mesophyll and druses in the mesophyll. Presence of epidermal prismatics may constitute a synapomorphy of the subfamily Nepetoideae or of a subclade within this subfamily consisting of the two largest tribes Mentheae and Ocimeae. The presence of narrow mesophyll prismatics seems to support a large clade of Lamioideae genera in a recent molecular phylogeny of the subfamily. Epidermal prismatics are found to be particularly frequent in closed calyces, calyces with a narrow mouth and internally hairy calyces. These findings and the position of the crystals in the calyces are regarded as supporting the hypothesis that calcium oxalate crystals protect the fruit against insect predators.
| Original language | English |
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| Journal | Plant Systematics and Evolution |
| Volume | 290 |
| Issue number | 1 |
| Pages (from-to) | 201-215 |
| Number of pages | 15 |
| ISSN | 0378-2697 |
| DOIs | |
| Publication status | Published - Dec 2010 |