Gonolobus cyclophyllus, also known by its synonym Matelea cyclophylla, is a distinctive vining plant. This caudiciform species, characterized by a thickened, often woody, stem base that stores water and nutrients, belongs to the milkweed family (Asclepiadaceae), now placed within the Apocynaceae. Native to Mexico, it is valued for its unique growth habit and striking flowers, appealing to collectors.
Identifying Gonolobus Cyclophyllus
Gonolobus cyclophyllus presents as a deciduous caudiciform vine that can either climb or trail, with its annual stems emerging from a thickened caudex. This caudex, which can be semi-subterranean in its natural habitat, is often raised by cultivators for display, growing from about 2 centimeters up to 20 centimeters in width over time. The caudex surface is typically covered with angular, soft, corky tubercles, giving it a textured appearance. From this base, herbaceous vining growth can extend up to two meters.
The plant’s foliage consists of heart-shaped, green leaves that are slightly fleshy to the touch. These leaves are deciduous, appearing during the rainy season and dying back during drier, dormant periods. Its flowers are particularly notable, displaying colors ranging from burgundy to brown, though green forms also occur. These symmetrical blooms, measuring approximately 2.5 centimeters (1 inch) wide, resemble a bat sea-star with five short corolla lobes.
The corolla surface of the flowers can be pubescent, adding to their intricate detail. While some descriptions note a fragrance, other sources indicate a carrion-like smell, which aids in attracting fly pollinators. Flowering typically occurs from spring through summer. Following successful pollination, the plant produces horn-like seed pods, known as follicles, from which seeds are dispersed.
Natural Habitat and Range
Gonolobus cyclophyllus is native to western Mexico, with its distribution spanning from Jalisco in the north, through states like Oaxaca and Guerrero, and reaching as far south as Chiapas. This species thrives in specific environmental niches within tropical deciduous and subdeciduous forests. The plant is typically found growing in the shade of rocks and fallen logs. It also colonizes limestone and volcanic cliffs, often occurring at altitudes ranging from 500 to 1000 meters above sea level.
In its natural setting, Gonolobus cyclophyllus prefers partial shade, where the caudex remains shaded while its vining leaves receive some sunlight. The plant requires well-drained, porous soil, often with an acidic composition, to prevent waterlogging and root issues. Although considered frost-hardy to about -1.1 to +1.7 degrees Celsius (30-35 degrees Fahrenheit), it generally prefers warmer conditions with a minimum average temperature of 15 degrees Celsius. It is susceptible to rot if exposed to cool, wet conditions for extended periods.
Ecological Role and Interactions
Within its native Mexican ecosystems, Gonolobus cyclophyllus flowers are adapted to attract specific pollinators. This scent serves as an attractant, drawing in insects that facilitate the transfer of pollen. The plant’s vining habit allows it to interact with other vegetation, using existing structures for support as it climbs or trails across the forest floor and cliffs. Its preference for growing among rocks and fallen logs integrates it into the understory community of tropical deciduous forests.
While specific insect host relationships or direct food sources for larger wildlife are not extensively documented, its presence contributes to the overall biodiversity of these specialized habitats. Its elusiveness and sparse populations in the wild suggest a distinct ecological niche.
Cultivation and Conservation Status
Gonolobus cyclophyllus can be cultivated, although it is often considered a plant for collectors due to its specific care requirements and slow growth rate. It is not commonly found in general horticulture. For successful cultivation, the plant needs a well-draining soil mix, ideally a porous and acidic blend, to mimic its natural substrate. Watering should be consistent during its active growing season, but significantly reduced or withheld when the plant enters dormancy, as it is prone to rot in overly wet conditions, particularly when leafless. Supporting its climbing vines is also beneficial for its growth habit.
Information regarding the specific conservation status of Gonolobus cyclophyllus on major lists, such as the IUCN Red List, is not readily available. This natural rarity suggests a certain level of vulnerability, particularly given the ongoing pressures of habitat alteration and climate change that affect many plant species globally. Further assessment would be needed to determine its precise conservation standing.