Amorphophallus Mirabilis: A New and Eye-Catching Arum Species From Myanmar’s Limestone Forest

Myanmar is home to a rich diversity of plant life, with many species that are endemic to the country.

Among them are the members of the Arum family (Araceae), which consist of terrestrial or aquatic shrubs, vines, or herbs.

One of the most striking genera in this family is Amorphophallus, which includes some 200 tropical and subtropical tuberous herbaceous plants.

Recently, a local plant enthusiast discovered a new and remarkable species of Amorphophallus, flowering in May and June 2023 in Hpa-an District, Kayin State.

He sent the samples to a researcher in Myanmar, who then collaborated with scientists from Xishuangbanna Tropical Botanical Garden (XTBG) in China to confirm that the specimens represent a new species.

Amorphophallus mirabilis: A Seasonally Dormant Herb with Eye-catching Foliage

(Photo : Matt Cardy/Getty Images)

The new species was named as Amorphophallus mirabilis, which means "wonderful" in Latin, to refer to its eye-catching foliage. It was published in Nordic Journal of Botany.

Amorphophallus mirabilis is a seasonally dormant herb, which means that it dies back to its underground tuber during the dry season and emerges again in the rainy season.

It is morphologically similar to A. dzui from northern Vietnam but differs by having a much longer peduncle (the stalk that supports the flower), a spathe (the large bract that surrounds the flower) that is pale purplish brown on the outside and pale maroon with fleshy warts on the inside, and stigmas (the female parts of the flower) that are entire or transversely bilabiate (two-lipped).

This new species is currently only known from its type locality in Hpa-an District, Kayin State, Myanmar, where it was found in the karst limestone forest growing in a crack of a moist sandstone rock under a closed to semi-open canopy of seasonal rain forest or dry evergreen forest, at an elevation of approximately 100 meters above sea level.

Researchers described the new species as having a unique and attractive appearance, with a single leaf that is divided into numerous leaflets, each with a white midrib and dark green margins. The leaf can reach up to 1.5 meters in height and 1.2 meters in diameter.

The inflorescence (the group of flowers) consists of a spadix (a spike of tiny flowers) that is up to 15 centimeters long, covered with male and female flowers, and a spathe that can be up to 25 centimeters long and 15 centimeters wide.

The spathe has a long and slender tube that curves upwards, and a broad and ovate limb that spreads horizontally. The spadix emits a foul odor that attracts pollinators, such as carrion flies and beetles.

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A New Record of Amorphophallus napalensis in Myanmar

During their on-going work on the taxonomy of the family Araceae in Myanmar, the researchers also newly recorded Amorphophallus napalensis, a tuberous geophytic plant (a plant that grows from an underground storage organ) that was previously known only from Nepal and India.

"This is the first report of the species in Myanmar, representing an important extension of its geographic distribution where it was found growing along the roadside/trail of Mt Victoria in Myanmar," said Mark Arcebal K. Naive, one of the authors of the study and a researcher at XTBG.

Amorphophallus napalensis is a small herb that grows up to 30 centimeters tall. It has a single leaf that is divided into three leaflets, each with a dark green upper surface and a purple lower surface.

The inflorescence consists of a spadix that is up to 10 centimeters long, with male and female flowers arranged in separate zones, and a spathe that is up to 15 centimeters long and 10 centimeters wide.

The spathe is green on the outside and purple on the inside, with a short and cylindrical tube and a lanceolate and reflexed limb. The spadix also produces a bad smell to attract pollinators1.

With the discovery of the new species and A. napalensis, Myanmar now holds 17 Amorphophallus species, five of which are endemic to the country.

The researchers hope that their findings will raise awareness and appreciation of the plant diversity and conservation in Myanmar.

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