Tristagma uniflorum (花韮, ハナニラ)

This native of Argentina & Uruguay is not mentioned in Ohwi's flora, but it's listed by the Ministry of the Environment as one of the 1,556 alien plants recognised as established in Japan. It's also very popular in gardens. I've seen it carpeting people's front gardens and then extending out onto the curb side and then even down the road a ways. It's apparently also naturalised in parts of the southeastern United States from Texas to Virginia, as well out west in California and Oregon, and even in Europe in France and the UK.

The English name is "spring starflower", for obvious reasons. The Japanese name is 花韮, (ハナニラ) which is read as "hananira" and means "flower garlic-chives". The second character alone, read just as "nira", is the word for Allium tuberosum (garlic-chives), which is an onion relative grown for its somewhat chive-like leaves. It's rare in western kitchens, but is ubiquitous in Asia. The spring star flower has similar looking and smelling leaves, hence the Japanese name.

In fact, under the APG II (Angiosperm Phylogeny Group) taxonomic system, the spring starflower has been placed in Alliaceae, the onion family, which also includes garlic-chives as well as any other chive. The move is part of a huge fracturing of the once enormous Liliaceae (lily family) into many smaller families, largely on the basis of new molecular (i.e. DNA) evidence. The scientific name is currently a matter of contention. It's often treated as Ipheion uniflorum (Lindl.) Raf., but in 1963 Hamilton P. Traub proposed that the entire genus Ipheion be collapsed into Tristagma, a closely related genus, yielding the name Tristagma uniflorum (Lindl.) Traub. Only more research will provide a more difinitive classification.


There's not too much more to say, and it's not very important culturally in Japan as it's a recent introduction. Plants have only basal leaves and a single flower on a scape that's usually less than 20 cm, both of which grow from a membranous subterranean bulb. The stamens are conspicuously unequal (3 long, 3 short), which separates this plant from most others in the onion family. The ones that I saw where nearly snow white, but they can be found flushed with a blue-violet.

Some links as usual:
Jepson Manual treatment (Flora of California)
Wikipedia entry (English)
Wikipedia entry (Japanese)