Phenology and floral morphology of the varieties of Columnea quindorisaraldensis Amaya, Álvarez, Ramos & Marín-Gómez (Gesneriaceae)

Columnea quindorisaraldensis is an endemic species of the Central Andes of Colombia, in which two botanical varieties are recognized based on calyx color and pollen morphology: var. quindorisaraldensis and var. porphyrocalycina. Although their distributions are partially sympatric, it is unknown whether this morphological differentiation is reflected in functional reproductive traits. To characterize and compare the flowering phenology and floral morphology of both botanical varieties, we monitored flowering and followed individual flowers in populations from the Barbas-Bremen Forest Reserve (Quindío, Colombia), complemented by floral morphometric measurements. We present preliminary results from the first sampling period (February–June 2026).

Flowering showed moderate synchrony, with a population flowering synchrony index (S) of 0.300 for var. quindorisaraldensis, 0.370 for var. porphyrocalycina, and 0.347 for the overall population. Two flowering peaks occurred during February–March and June. Both botanical varieties exhibited a well-defined protandrous sequence, with no differences in total floral longevity or female-phase duration. However, var. porphyrocalycina showed a significantly longer male phase (2.2 ± 0.8 vs. 1.5 ± 0.7 days; p = 0.042).

Morphological comparisons revealed longer corollas and pistils in var. porphyrocalycina (p < 0.05), whereas corolla diameter, basal constriction, and stamen length did not differ between the botanical varieties. Principal component analysis consistently separated the two botanical varieties within the morphospace.

These results represent the first quantitative assessment of the reproductive biology of C. quindorisaraldensis and suggest incipient functional differentiation with potential implications for pollination dynamics between sympatric botanical varieties.