Leptocereus

Segmented stems and three lineages

Leptocereus combines stems formed from successive segments, varied growth forms and areoles often sunken into undulate rib margins. Plastid DNA analyses in 2020 and 2021 distinguished the Cuban lineage, the Hispaniolan and Puerto Rican lineage, and former Dendrocereus. Including the last group preserves the genus as a single lineage of descent. The studies differed in the branching order among these three groups, so the detailed history of their divergence remains under investigation. [Barrios et al. 2020a, pp. 4–12 in the 2020 study, pp. 20–22 in the 2021 study] [Majure et al. 2021a, pp. 4–12 in the 2020 study, pp. 20–22 in the 2021 study]

Flowers, short shoots and pollinators

Most studied leptocerei have flowers that open in the evening or at night. Some western Cuban populations have also been described as beginning anthesis during the day and retaining flowers longer. In Hispaniolan species, flowers may develop on short shoots, brief terminal segments with densely arranged areoles. Flowers also occur near the tips of ordinary stems. Species of former Dendrocereus have particularly long, narrow floral tubes. [Hoxey et al. 2023b, p. 22 in the 2023 revision, pp. 7–10 in the 2020 study] [Barrios et al. 2020a, p. 22 in the 2023 revision, pp. 7–10 in the 2020 study]

For L. leonii, an experiment published in 2026 confirmed effective nocturnal pollination, self-incompatibility and visits by the bat Monophyllus redmani. These results concern one species and a particular population. Differences in tube size, colour and nectar secretion across the genus require verification of actual pollinators, because flower structure alone suggests only a possible interaction type. [Ruiz and Barrios 2026, pp. 9–15]

Fruits and recruitment

Fruits of many species have thick walls, spiny areoles and seeds surrounded by mucilage. Densely armed fruits, smooth fruits of former Dendrocereus, red fruits of L. leonii and weakly mucilaginous fruits of L. cremnophilus illustrate this variation. Stems of some species root after contacting the substrate. Animals are likely involved in dispersal in some populations, but hypotheses concerning particular iguanas or extinct dispersers must be distinguished from documented observations. [Hoxey et al. 2023b, pp. 11–14, 24–26, 64–65 in the 2023 revision, pp. 8–11 in the 2020 study] [Barrios et al. 2020a, pp. 11–14, 24–26, 64–65 in the 2023 revision, pp. 8–11 in the 2020 study]

Germination and temperature

A controlled experiment published in 2025 studied 10 Cuban taxa under their source name concepts. It used 7 replicates of 25 seeds per treatment and an initial 28-day observation period. The highest germination was generally obtained at 25°C or under daily alternation at 25/30°C. Values declined at 25/35°C, with important differences among taxa. Light for 8 hours per day promoted germination relative to darkness. For L. assurgens and material identified as L. ekmanii, limited seed availability allowed only 2 temperature treatments. [Barrios et al. 2025, pp. 3–8, 11–13]

Seeds from hot treatments were transferred for another 28 days to 25°C in light. Some then germinated, while many remaining seeds still had viable embryos. Heat inhibition of germination must therefore be assessed separately from loss of viability. The climate projections in this paper concerned 2070 and conditions at specific Cuban sites. They are not measurements of future population sizes or safe overwintering temperatures. [Barrios et al. 2025, pp. 4, 8, 10–14]

Documented sowing and the scope of guidance

At Gibraltar Botanic Gardens, seedlings of Hispaniolan species were raised from washed seeds surface-sown on crushed lava of 3–6 mm particle size. Artificial light and temperatures of about 18–20°C at night and 25–30°C by day were used. Seeds were left uncovered. Capillary watering limited displacement of seeds and small seedlings. They usually germinated after 2–3 weeks, and seedlings were pricked out after about 4–6 weeks. This describes the research protocol used, without comparative testing of all substrate and cultivation options. [Hoxey et al. 2023b, pp. 7]