Eriosyce coimasensis

Name and structure

Eriosyce coimasensis is an accepted species, formerly treated, among other names, as E. senilis subsp. coimasensis. It has a barrel-shaped stem reaching about 30 cm in height, 13–21 ribs and numerous spines in its areoles. The species is associated with dry scrub in central Chile, and reproductive research was conducted at Las Coimas, its type locality [Guerrero et al. 2019] [Cádiz-Véliz et al. 2021] [2-WWW].

Tubular flowers measure about 5–7.5 cm. They have crimson tepals with yellow bases and a nectar chamber widening towards the base. Inner perianth parts point inwards, while outer parts curve outwards. This arrangement determines access to nectar and contact between visiting animals and the reproductive organs [Cádiz-Véliz et al. 2021].

Pollination and reliance on cross pollen

The experiment included cross-pollination, hand self-pollination and flower isolation. Isolated flowers without hand pollination produced no seeds. Self-pollination yielded seeds in only one individual, whereas cross-pollination performed much better. This indicates strong self-incompatibility in the study population and the importance of pollen transfer between plants [Cádiz-Véliz et al. 2021].

Field observations recorded visits by Patagona gigas to flowers of exposed plants. Nectar was studied separately in plants maintained under common cultivation conditions. In that material, secretion was concentrated in the morning and larger flowers produced more nectar. The result describes the tested conditions and helps explain floral attraction to hummingbirds [Cádiz-Véliz et al. 2021].

Shrubs and reproductive success

In 2018 and 2019, plants beneath Flourensia thurifera and in open microsites were compared with and without cages excluding hummingbirds. Exposed plants accessible to birds performed best. They produced about 80% of all seed-bearing fruits and 76% of seeds in the entire experiment. Plants beneath shrubs performed less well, resembling caged plants [Cádiz-Véliz et al. 2021].

Stems were larger beneath shrubs, yet larger size accompanied lower seed production. The authors relate this pattern to restricted hummingbird access and possible pollen limitation. Conditions for fruit maturation or nectar properties may also contribute. This single-site study supports conserving the habitat and pollinator system as a whole, while shelter benefits for seedlings require separate evaluation [Cádiz-Véliz et al. 2021].

Related articles

Related plant cards