New Zealand Alpine Bulbinella

Author: Ross Graham
Published on: Nov 16, 2001

New Zealand Alpine Bulbinella:

New Zealand is quite unusual in having comparatively few bulb species. This may be due to its long isolation as an island group with bulb seed not getting here as easily as other types of plants. But apart from that I really don't know why this should be so. In this article I want to talk about the NZ Bulbinella species.

Bulbinella are in the Lily family. Other New Zealand Genera in this family are Astelia and Herpolirion novae-zelandiae; the worlds smallest lily. Bulbinella are tufted perennial herbs which die down to a fleshy rootstock in winter. Of the 20 species worldwide 6 grow in New Zealand.

The distribution of Bulbinella is unusual in that NZ is the only place it grows outside of Africa. The New Zealand flora is primarily evergreen due to the mild oceanic climate, so this also makes Bulbinella here a little unusual. Flowers are grouped together into racemes and are either yellow or white with all the 6 New Zealand species being yellow. Identifying the species in New Zealand is best done by looking at the seed capsules, with the shape of the capsule and the presence or absence of dried tepals being the features to look for.

In terms of horticulture B. hookeri, B. rossii, B. gibbsii var. balanifera and B. angustifolia are probably the most well known. Of those, if you could choose any, B. hookeri and B. rossii are probably the pick of the bunch. B. rossii from the Auckland and Campbell Islands in the Subantarctic Islands is one of the so called mega-herbs and is difficult to get seed of and needs a cool climate, so is unsuitable for most places in New Zealand.

By the way, I'd sell my granny for good seed of it, as I think Dunedin's climate is just about suitable for it, especially where I live at almost 300m in Halfway bush.

Where it hasn't been decimated by stock in boggy places in the subantartics there are whole fields of B. rossii and other mega-herbs like Stilbocarpa polaris and Anisotome latifolia making one of the loveliest sights for plant lovers. As far as the Subantarctics are concerned I consider them to be an alpine environment because for most of them treeline is at or close to sea level. Bulbinella species here grow in boggy or damp places and often become very common in damp farm areas that have been burnt over and grazed. In such places they turn the pastures yellow with their flowers in summer.

Of the other species B. talbotii may be a very attractive species for growing in pots or in the rock garden as it is very small with the flower only a few cms high and leaves spread almost flat over the ground. It is very local though only occurring in the Gouland Downs, North West Nelson. Salmon's "A Field Guide to Alpine Plants of New Zealand" has a good photo of it growing in a pot.

Cultivation is relatively easy for all except B. rossii. The best way is probably with division of the rootstock but seed is simple enough with a little patience. From my experience seed will germinate fast if it is left over the winter in a seed tray that is exposed to frosts and cold weather. Otherwise it will germinate eventually, maybe after 18 or more months. Plants will flower after 2 years from germination. They don't seem to need any special conditions as long as they are not allowed to dry out too much. Addition of some peat to the soil for the rock garden might help.

Ross Graham

Dunedin,

New Zealand.

Please visit my website on the Cultivation and Ecology of New Zealand Alpine Plants: http://www.geocities.com/alpine_plants_n... containing seedlist on page: http://www.geocities.com/alpine_plants_n...