User:Oases Bonsai

Uncarina roeoesliana  

                

Origin, Habitat and Ecology: Uncarina roeoesliana is deciduous tender tropical shrub of Pedaliaceae family, endemic to Tolanaro district of south-west Madagascar.

Where it grows on lime stone rocks at 100-500 meters above sea level need well drained soil with lots of water and sun in sub-arid climate. In the wild it reaches 2 meters high.

It was first described by Werner Rauh in 1996.

Description: (stem,leaves and flowers) Uncarina roeoesliana develops a caudex at the base, stems are stout that becomes thicken with age, reach about 6 feet. Leaves are thick  soft velvety palmate 3-5 lobed more or less incised  gray green in color with smooth margins some time reddish petioles,and puts out beautiful,so fun to touch fuzzy leaves.

This species profusely bloom in summer with lot of small yellow flowers by size 1.5-2 inches(new hybrids in  red,pink, orange,dark and light yellow, white flowers also introduce recently). It is a much smaller growing species then its cousins. It can flower even when young. It also flowers within 5 months of germination.U. roeoesliana is also easiest one to flower in his family.

It is partially deciduous, in winter it dormant and will drop most of old leaves but young small leaves may remain, it’s depend on winter temperature. The leaf losing mechanism is based on warmth and sun light.

In summer they grow fast and need of lots of water ,sun and fertilizer. Uncarina grows in well drained soil mildly alkaline(7.6-7.8pH) and drought tolerant but unlikely succulents, prefers lots of water among with sun. They love sun but also give good result in partial sun.

Uncarina fruits are capsule approx 3-5 cm long, looking bizarre with small inwardly pointed sticky hook like harpoons,so don’t touch with your fingers.

Pollination: Flowers are bisexual have anthers and stigma but anthers never shed pollen, its done by some insects like bees or some pollen eating eating beetles.In the floral tube they push the stigma lobe to get anthers stigma lobe is moved down on top of insects and scrapes the pollen off hence pollination done.

Cultivation and Propagation: Uncarina are not common in cultivation because seed does not germinate easily although they can germinate after many years and lay burred in soil for a long time. Cuttings not root easily. Air-layering is a successful substitute .Rainy season is good to germinate seeds,if retrain moisture and temperature is suitable  seeds sprout one or two week later after sowing.

Bibliography: Major references and further lectures

1) Rauh, W. 1996. “Uncarina roeoesliana Rauh spec. nov., eine neue Art aus Südwestmadagaskar.” Kakteen And. Sukk. 47(1): 13–18.

2) Werner Rauh, Herman Schwartz “Succulent and xerophytic plants of Madagascar”, Volume 2 Strawberry Press, 1998

3) Reference article Rauh, W. 1998. “Blütenfarbe von Rosa bis Gelb: Zweiter Teil des Artikels über die Gattung Uncarina aus Madagaskar.” Kakteen And. Sukk. 49(10): 229–233

4) Reference article Rauh, W. 1998. “Uncarina, die "Hakenstachelige": Eine nur auf Madagaskar vorkommende Gattung der Pedaliaceen.” Kakteen And. Sukk. 49(9): 205–209.