Leuenbergeria zinniiflora

Origin and stem traits

According to POWO, the natural range includes Cuba, and habitats belong to the seasonally dry tropics. Older trunks retain spines and have brown bark. Young areoles may be covered with rusty brown hairs. These traits were compared with the almost unarmed, rusty-coloured trunk of Leuenbergeria marcanoi. [2-WWW] [Areces-Mallea 1992]

On older branches, Leuenberger observed remnants of short flowering branches and developing new flowering shoots. Descriptions of functionally dioecious plants must distinguish male from female flowers. They differ in the size of the part enclosing the ovary, among other traits. [Leuenberger 2008] [Areces-Mallea 1992]

Leaves, flowers and fruits

The plant develops into a small tree, usually 4–8 m tall. Several leaves arise from each areole on short shoots, and older branches form numerous short flowering branches. Flowers have a pink to purplish pink perianth. In male flowers, numerous stamens surround a short, reduced pistil. Female flowers have an enlarged ovary and small, sterile stamen remnants. [Leuenberger 1986, Pereskia zinniiflora description]

The fruit is nearly spherical to flattened, with a distinct depression or flat area at the top. In descriptions cited in the monograph, its diameter reaches about 1.4–3 cm. Seeds are black and glossy, mostly about 2.8–3 mm long. Fruits of Leuenbergeria marcanoi are larger and more strongly flattened, so fruiting material helps distinguish these similar species. [Leuenberger 1986, Pereskia zinniiflora description]

Historical field observations come from dry coastal scrub and low forests of southern Cuba. Flowering was recorded mainly from March to August and fruits from May to August. These periods describe local phenology and do not establish a treatment calendar for a greenhouse in Poland. [Leuenberger 1986, Pereskia zinniiflora description]

Roots that changed the species description

Areces-Mallea's 1992 key gave the absence of tuberous roots as a trait separating this species from Leuenbergeria quisqueyana. During removal of a specimen from a warm greenhouse in Berlin-Dahlem in 1994, however, three large thickenings were found. The largest was about 60 cm long and up to 14 cm in diameter. Leuenberger published the observation in 2008. The earlier assessment was based partly on young plants with fibrous roots, so the trait must also be considered in relation to age. [Areces-Mallea 1992] [Leuenberger 2008]

Limits of root propagation

Detached thickenings remained fleshy for a long time and even produced new root tips. No new shoots appeared, however. Survival of storage tissue and regeneration of a complete plant are different capacities. The observation described does not confirm successful propagation of this species from detached tuberous roots alone. [Leuenberger 2008]