Pair-flowered cymes in the Lamiales: structure, distribution and origin.

ABSTRACT:

Background and aims

In the Lamiales, indeterminate thyrses (made up of axillary cymes) represent a significant inflorescence type. However, it has been largely overlooked that there occur two types of cymes: (1) ordinary cymes, and (2) 'pair-flowered cymes' (PFCs), with a flower pair (terminal and front flower) topping each cyme unit. PFCs are unique to the Lamiales and their distribution, origin and phylogeny are not well understood.

Methods

The Lamiales are screened as to the occurrence of PFCs, ordinary cymes and single flowers (constituting racemic inflorescences).

Key results

PFCs are shown to exhibit a considerable morphological and developmental diversity and are documented to occur in four neighbouring taxa of Lamiales: Calceolariaceae, Sanango, Gesneriaceae a

SUBMITTER: Weber A 

PROVIDER: S-EPMC3828946 | biostudies-literature | 2013 Nov

REPOSITORIES: biostudies-literature