Phenology and nurse plant of Sotoa confusa (Garay) Salazar (Orchidaceae) in the Southern Potosino Zacatecano Highlands

Abstract

Sotoa confusa is a little conspicuous terrestrial orchid that is distributed in arid and semi-arid land of Mexico and south of USA, its life history is poorly known, so phenology and interaction of this species with shrubs was studied; its bloom occurs in March and fructifies in April (the driest period of the year), latter, from July to September it develops leaves, which disappear in October, so this orchid remains eight months without leaves. By other hand, S. confusa does not grow in areas with bare soil, so it shows preference to grow under the canopy of plants such as Dodonaea viscosa, Opuntia imbricata, O. robusta, O. leucotricha and Pittocaulon praecox; however, it shows a negative association with Jatropha dioica. The survival strategy of this plant in arid environments is to grow under the canopy of other plants that provide a favorable microclimate and develop leaves only during rainy seasons.