Selaginella, collectively known as spike moss, are not your ordinary kind of plants. Classified among the "lower plants" for their lack of flowers and seeds, they belong to a group which dominated the Earth's surface long before flowering plants and trees made their appearance. Fossil finds trace their origins to the Carboniferous period 290-354 million years ago. As a genus, they comprise more than 400 species worldwide.

One of Thailand's leading taxonomists, the late Tem Smitinand, listed 16 Selaginella species in his volume titled Thai Plant Names, but it is possible that since he compiled the book in 1980 and its revision by the Forestry Department's Forest Herbarium in 2001, more have been identified. In any case it's a good bet that more are waiting to be discovered in their natural habitats. Herbaceous, creeping, erect or sprawling plants with branching, scale-like leaves, several species can be found in organically-rich, moist forest floors and near streams while others, such as Selaginella tamariscina and Selaginella lepidophylla, grow in dry, rocky habitats.

‘Selaginella willdenowii’ is commonly known as peacock fern because of its iridescent, bluish-green leaves.
In periods of drought some species curl their leaves and branches inwards, turning the plants into dry, seemingly lifeless, greyish-green or brown balls. In the deserts of Texas and Australia, these balls of dry plants are blown by the wind for kilometres. Then, as the rains come and the plants are saturated with water, they spring back to life and look fresh again, giving them the common name "resurrection plant".
Likewise, in dipterocarp forests where forest fires occur regularly, Selaginella curl into a ball. Although singed by the fire, they survive and come back to life when they get enough water. This survival mechanism is probably the reason why this genus in the Lycopodiopsida class of plants has survived from ancient times to this day.
In Chiang Mai, Chiang Rai, Lampang, Nan and Phrae provinces, the young leaves of Selaginella argentea are relished in a dish called kaeng om and villagers collect them in the wild to cook as food or to sell in the market. In Thai, S argentea is known as pho kha ti mia (merchant beats wife). No matter how long it is boiled, the leaves remain crisp and look uncooked, and as the tale goes, a man beat his wife for serving what he thought was uncooked food, hence the Thai common name.
Selaginella tamariscina, known in Thai as dok hin, can be found in elevations of 600-1,000m above sea level, from Kanchanaburi northwards to Chiang Dao in Chiang Mai. It occurs naturally in Thailand, Vietnam, China and Korea, the Philippines and Indonesia. In these and neighbouring countries, spike moss in general is used as a herbal remedy for a broad spectrum of ailments.

Ferns tower over spike moss in the organically-rich, moist forest floor.
According to the book, Cryptogams: Ferns and Fern Allies, published by the Indonesia-based Plant Resources of Southeast Asia (Prosea) Foundation, the entire S tamariscina plant has been used to treat jaundice, hepatitis, burns, respiratory diseases and haemorrhoids in Vietnam. In Malaysia and the Philippines the whole plant is boiled to a concentrated decoction and drunk to treat coughs, gastro-intestinal bleeding and excessive menstrual flow. Powdered, the herb is applied to wounds. In traditional Chinese medicine, S tamariscina is used to treat advanced cancer, pulmonary disease and, in combination with acupuncture, diabetes. China exports the herb to Hong Kong, Singapore, Malaysia and Germany as well as Thailand, where it can be bought in pharmacies selling Chinese herbal medicine. Various other Selaginella species have been found to have anti-tumour, anti-viral and anti-oxidant properties.
In the garden, they make beautiful decorative plants with their lush foliage, which are green, like Selaginella delikatula, known in Thai as kut pha or phak kut hin; or bluish, like Selaginella siamensis, or phak nok yoong; or iridescent, like Selaginella willdenowii, known in Thai as rang kai. A scrambling plant, the latter is commonly known as peacock fern because of the iridescent, bluish-green colour of its leaves; it is not, however, a fern.
Spike moss likes high humidity and thrives best in shade or filtered light, in soil rich in organic matter and relatively moist but not soggy.
Like ferns, they can be propagated from spores or by plant division. Sometimes, you don't even have to do anything. In our country home, two of our greenhouses containing ferns and bromeliads are carpeted by spike moss, with mother nature propagating the plants while we are away in Bangkok.
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