Name and scope of research material
Eulychnia breviflora Phil. is the accepted name in Plants of the World Online. Its synonyms include E. saint-pieana, E. barquitensis, E. longispina and E. breviflora var. tenuis. E. iquiquensis and E. ritteri, treated in some older accounts as subspecies of E. breviflora, now have separate species rank in POWO. [2-WWW]
Plants from Lomitas in Pan de Azúcar were described in Stanton and colleagues' study as E. saint-pieana. Here, the results are assigned to E. breviflora (called E. saint-pieana in that study) using current synonymy. They concern a specific coastal population with abundant lichens on the stems. [2-WWW] [Stanton et al. 2014, p. 1275–1277]
Growth form, spines and the hairy flower
The plant forms branched columnar stems. The description cited in the official SIMBIO account generally gives a height of 2–3 m and 10–13 ribs. Young spines are darker and turn grey with age. An areole bears shorter marginal spines and much longer central ones. Scales and areoles with long, woolly hairs cover the lower flower region and its short tube. This is one of the group's most visible features. [23-WWW]
In this description, flowers are bell-shaped, white and pink, 7–8 cm long. Spherical fruits have white, acid pulp and numerous black seeds. Hairiness also persists on the fruit surface. The SIMBIO account bases these features on Hoffmann and Walter's 2004 monograph. Caution over taxon circumscription is retained when comparing older data, since POWO recognises the former var. taltalensis as E. taltalensis. [23-WWW] [2-WWW]
Habitat and local water balance
POWO gives a natural range from west-central Atacama to northwestern Coquimbo. The population studied in Pan de Azúcar occupies a rocky coastal area influenced by ocean fog. Lichens, including Ramalina usnea and Usnea spp., grow on the spines and stem surface. They create extra surface area for intercepting droplets and alter airflow close to the cactus. [2-WWW] [Stanton et al. 2014, p. 1275–1277]
On 15 cacti, lichens were removed from the northern or southern half of the stems, with a control group retained. Removal from the northern part was associated with faster soil drying after rare rain. Measurements near the stem indicated lower daytime temperatures and vapour pressure deficit with lichens present. The effect includes reduced atmospheric evaporative demand. The study measured microclimate and soil water, without directly measuring cactus gas exchange. [Stanton et al. 2014, p. 1276–1282]
Flower position on the stem
Warren and colleagues recorded the positions of 180 buds and open flowers on 40 plants along an approximately 100-kilometre transect. Reproductive organs predominated on the northern side of both whole plants and individual stems. Flowers arise laterally, so this orientation can result from selection of their development site on an upright column. [Warren et al. 2016, pp. 2–3]
The authors propose that developing flowers near well-lit parenchyma reduces the transport cost of assimilates, compounds produced during photosynthesis. They also consider flower warming a possible benefit for visiting insects. Directional data confirm organ positions. Sugar flow, flower temperature and increased pollination effectiveness were not measured in this experiment. [Warren et al. 2016, pp. 3–4]
Water availability and seed production
The abstract of a 2025 study describes three populations along an aridity gradient. Under drier conditions, flowers were smaller and plants displayed more of them. Phenology, the course of development over time, also changed. The bud phase was shorter, flowering began later and lasted longer. Pollinator richness and visit frequency were similar among populations. [Piñones-Tapia et al. 2025, abstract]
In a field experiment, adding water during a dry year increased seed number, with similar fruit set. Measured flower traits and visitation parameters showed no demonstrated response to short-term irrigation. The result separates maintenance of flowering from investment in seeds. The available abstract allows the response direction to be described, but gives neither the detailed water dose nor effect size. [Piñones-Tapia et al. 2025, abstract]
Cultivation and the older P064 description
Konrad Szychowski's private archive preserves an older review recommending a porous growing medium and restrained watering for E. breviflora. This material remains available as profile P064. Coastal fog co-occurs with an airy, rocky environment. Water retention on lichens and its supply to roots are two separate processes there. [Sukulenty b.d.a, skan, p. 4–6] [Stanton et al. 2014, skan, p. 4–6]
In a container, the growing medium should release excess water freely, and the plant should receive abundant light and ventilation. The RHS general guide links cactus watering to growth and drying of the medium, and rest to reduced watering. Pot size is matched to root system size. These conditions provide a general basis for care under cover, supplementing the archival guidance for the species. [1-WWW] [Sukulenty b.d.a]
Related articles
Materials from the author's archive
The species also appears in Konrad Szychowski's private material archive. [Romulski b.d., file p. 5]
Synonyms and names in the literature
Eulychnia saint-pieana · Eulychnia barquitensis · Eulychnia breviflora var. tenuis · Eulychnia longispina · Eulychnia saint-pieana var. barquitensis · Eulychnia saint-pieana subsp. tenuis · Eulychnia procumbens [2-WWW]