In December 2025, Japan's Tsukuba Botanical Garden, operated by the National Museum of Nature and Science, announced a remarkable achievement: the successful artificial pollination of Welwitschia mirabilis, known in Japan as "Kisoutengai" (meaning "beyond imagination"). A plant that was placed in the greenhouse in 1992 finally flowered for the first time after 33 years, leading to this groundbreaking result.

Welwitschia is an endangered species found only in Africa's Namib Desert. Often called a "living fossil," this plant has fascinated scientists for over 160 years due to its extraordinary biology. The successful pollination represents a significant step forward in the conservation and research of this rare species.

What is Welwitschia?

Basic Information

Welwitschia mirabilis is a gymnosperm belonging to the family Welwitschiaceae. It holds the unique distinction of being a "one family, one genus, one species" plant, there are no other living relatives in its taxonomic family.

The plant was first discovered by Austrian botanist Friedrich Welwitsch in 1859 in the Namib Desert of Angola. When he first encountered it, he reportedly knelt down on the burning sand and simply stared in disbelief. The Japanese name "Kisoutengai" (奇想天外), meaning "beyond all imagination," perfectly captures the plant's bizarre appearance. It is the national flower of Namibia and even appears on the country's coat of arms.

Extraordinary Biology

The most remarkable feature of Welwitschia is that it produces only two leaves throughout its entire lifetime. After germination, the plant develops two cotyledons followed by two true leaves, and never produces any more. These two leaves continue growing from their base throughout the plant's life, extending at a rate of approximately 13.5 centimeters per year.

In the wild, specimens have been documented with leaves reaching 1.8 meters in width and over 6 meters in length. As the leaves grow, the tips gradually die and the leaves split lengthwise due to wind and desiccation, sometimes giving the appearance of multiple leaves.

The lifespan of this plant is truly astonishing. Carbon-14 dating has confirmed individuals over 2,000 years old, with some estimates suggesting that certain specimens may be as old as 3,000 years.

Adaptation to Extreme Conditions

The Namib Desert, where Welwitschia grows naturally, is one of the world's oldest deserts. It features extremely harsh conditions with annual rainfall of only 25-100 millimeters, and periods of over 150 days without any rain.

Remarkably, Welwitschia does not possess water-storing tissues like cacti. Instead, it has developed unique survival strategies.

Deep Root System: The main taproot extends over 3 meters deep, accessing groundwater reserves far beneath the desert surface.

Fog Harvesting: The Namib Desert experiences frequent fog when the cold Benguela Current meets hot desert air. Welwitschia leaves have stomata on both surfaces and a thick cuticle layer that efficiently absorbs atmospheric moisture.

CAM Photosynthesis: The plant uses Crassulacean Acid Metabolism (CAM), absorbing carbon dioxide at night while keeping stomata closed during the day. This is extremely rare among gymnosperms.

Challenging Reproduction

Welwitschia is dioecious, meaning male and female reproductive structures occur on separate plants. It takes approximately 25 years for a plant to reach reproductive maturity. Pollination is primarily achieved through wind and insects, particularly bugs from the family Pyrrhocoridae.

Female plants produce 10,000 to 20,000 winged seeds annually, but most become infected with Aspergillus fungus and die. Seeds require at least 12.5 millimeters of rainfall and 3-21 days of moisture to germinate. Such conditions occur in the Namib Desert perhaps once every 50 years, resulting in extremely low natural reproduction rates.

The Successful Pollination at Tsukuba

Background

Tsukuba Botanical Garden planted Welwitschia specimens in 1992 and has maintained them in the Savanna Greenhouse. While a male plant has flowered nearly every year, the female plant had never bloomed, until now.

In July 2025, after 33 years of cultivation, the plant finally flowered. The shape of the strobilus (cone-like reproductive structure) confirmed it was a female plant. This was the first female flowering at the facility.

The Pollination Process

Fortunately, male and female plants were positioned close together. Staff member Hiromi Kobayashi and her colleagues used tweezers to carefully transfer tiny pollen grains, just about 1 millimeter in size, from the male to the female plant every few days.

In natural conditions, wind and insects handle pollination, but in the controlled greenhouse environment, human intervention was necessary. With no precedent to follow, the team worked through uncertainty, unsure whether their efforts would succeed.

Seed Discovery

On the morning of December 16, 2025, during a routine inspection, staff discovered seeds that had fallen near the female plant. The seeds were enclosed in wing-like structures (designed for wind dispersal) and measured approximately 3 centimeters including the wings. This was definitive proof that artificial pollination had succeeded.

"We had no precedent, so I was anxious about whether we had pollinated properly, but I'm very happy," said Kobayashi.

Future Plans

The collected seeds will be used for propagation experiments at the garden and will also be shared with other research institutions. Garden Director Tomohisa Yukawa stated, "It's extremely rare to see seeds. We're exhibiting them alongside the plant, so please come visit."

Conservation Significance and Future Challenges

Climate Change Threats

Recent research has raised serious concerns about climate change impacts on Welwitschia habitats. In northern Namibia's Kunene region, habitat suitability is predicted to decrease by approximately 70% by 2050. Under IUCN criteria, populations in this area would qualify as "Endangered (EN)."

Importance of Ex-situ Conservation

Given these threats, the successful pollination at a Japanese botanical garden holds significant meaning for ex-situ conservation (conservation activities outside natural habitats). Establishing seed production and breeding techniques could contribute to protecting and potentially restoring wild populations in the future.

Where to See Welwitschia in Japan

Currently, the main facilities in Japan where visitors can observe Welwitschia include:

  • Tsukuba Botanical Garden, National Museum of Nature and Science (Tsukuba, Ibaraki)
  • Sakuya Konohana Kan (Osaka)
  • Higashiyama Zoo and Botanical Gardens (Nagoya, Aichi)
  • Fukuoka City Botanical Garden (Fukuoka)
  • Yamashina Botanical Museum (Kyoto)

In Japan, there is growing interest in rare plant conservation at botanical gardens and increasing awareness about endangered species. How does your country approach the conservation of such "living fossils"? Are there breeding programs at botanical gardens? What discussions are taking place about climate change impacts on rare plants? We'd love to hear your thoughts in the comments!

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