Abstract

OCAMPO-VELAZQUEZ, Rosalía V; MALDA-BARRERA, Guadalupe X  and  SUAREZ-RAMOS, Guadalupe. Reproductive biology of mexican oregano (Lippia graveolens Kunth) in three exploitation conditions. Agrociencia [online]. 2009, vol.43, n.5, pp.475-482. ISSN 2521-9766.

Mexican oregano (Lippia graveolens Kunth) is collected in nearly the entire national territory and its use coincides with the plant blooming, which limits the development of fruits and seeds. Reproduction aspects of L. graveolens were studied in individuals of a wild non used population (San Juan Raya, state of Puebla, México), another wild population under permanent use (La Salitrera, state of Guanajuato), and a population under cultivation (Universidad Autónoma de Querétaro, state of Querétaro, México). A description of the growth of its flowers was included, as well as the type of reproduction and an evaluation of the fruit production. L. graveolens presented undetermined inflorescences of the capitate spike type with a highly changeable number of flowers per inflorescence (from two to 20), always small flowers (4 mm). Flowers are hermaphrodites, unlike the other species of the same genus that are dioic. Therefore even when their use coincides with the flowering period, there is no need of a special practice for its use by recollectors. The different management conditions did not alter the sexual expression neither the production of fruits which varied from 0.9 to 6.4 %; but there was a reduction in the production of fruits possibly due to the absence of pollinators; 61.8 % of inflorescences of each plant did not render fruits; in 38.2 % one to eight fruits per inflorescence were detected, of which 93 % formed a well developed seed and the other one aborted, and the remaining 7 % presented two seeds per fruit. It is important to know about seed production at the moment of extraction as it is the only way of natural reproduction of this species.

Keywords : Lippia graveolens; flowers; blooming; hermaphrodite; fruit production.