The Himalayas are a stunning natural wonder that truly deserve to be called “epic”. These towering peaks are home to some of the highest points on Earth and are renowned for presenting formidable challenges to adventurers from around the world.
Despite their elevation, life thrives on these mountains, including a fascinating plant species that is related to rhubarb, a common garden and pie ingredient in more hospitable climates. This peculiar plant can be found among sprawling shrubs and diminutive herbs, further adding to the intrigue of the Himalayas.
Let me introduce you to the remarkable Rheum nobile, also known as the noble rhubarb. This plant truly lives up to its noble name, as it grows in some of the harshest conditions on earth. Found at elevations ranging between 13,000 and 15,000 feet (4000-4800 m), this species is a true survivor. Despite facing extremely low temperatures and damaging UV radiation, Rheum nobile can grow up to an impressive height of 6 feet, making it the tallest plant for miles around.
While most plants in alpine zones grow prostrate over the ground, taking refuge behind rocks, Rheum nobile stands tall and proud. It’s no wonder this member of the buckwheat family has earned its noble status.
One of the most notable features of this particular plant is its impressive spire made up of translucent bracts. These unique leaves have been modified and lack chlorophyll, which means they do not contribute to photosynthesis. Instead, their primary role is to provide protection and warmth for the plant’s flowers, which would be susceptible to damage from the elements without this protective shield.
The bracts contain specialized pigments that filter out harmful UV wavelengths while creating a favorable environment for the flowers and seeds to grow. Essentially, this plant creates a greenhouse-like atmosphere for itself.
The Rheum nobile plant experiences higher temperatures than its surrounding environment due to its high elevation. This provides an advantage to its reproductive process. However, the lack of pollinators at such heights presents a challenge for the plant. To overcome this, Rheum nobile uses both visual and chemical cues to attract pollinators. Its unique appearance stands out in the bleak surroundings while its chemical signals entice pollinators to come closer.
The Rheum noble plant has formed a mutually beneficial relationship with fungus gnats that reside at high altitudes. The plant produces a unique chemical compound that attracts female fungus gnats. These females lay their eggs in the plant’s developing seeds but also end up pollinating more flowers than they parasitize. It’s a delicate balance that has been struck within this mountainous environment. In exchange for pollination services, the fungus gnats have a safe and warm location to raise their offspring that is protected from the harmful effects of UV radiation.