T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Watsonia meriana var. bulbillifera (Watsonia)

Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Iridaceae
Subfamily: Ixioideae
Tribe: Watsonieae
Genus: Watsonia
Species: W. meriana
Binomial name: Watsonia meriana
Subspecies: Watsonia meriana var. bulbillifera
Synonyms: Watsonia bulbillifera, Watsonia angusta,Watsonia meriana
Common names: Watsonia, Bugle lily, Bulbil bugle lily, Bulbil watsonia, Merian's bugle lily, Wild watsonia

Watsonia meriana var bulbillifera is native to southern Africa but is now naturalised in New Zealand were it is a weed of roadsides, railways, gardens, waterways, pastures, coastal environs, disturbed sites and waste areas.
It is an erect perennial herbaceous plan emerging each year from underground corms and growing 100-180 cm tall, but can reach up to 2.5 m in height. It dies back after flowering.
The erect rounded; flowering stems (up to 20 mm thick) are often reddish in colour and are only rarely branched near their tips.
The large light green leaves are linear in shape with entire margins and acute apices. They are >80 cm long and 1-5 cm wide. Most of the leaves arise from the base of the plant, but a few smaller leaves are alternately arranged along the stems.
Flowering occurs mainly during spring and early summer. The tubular, slightly curved flowers (>8 cm long and >4 cm across) are widely spaced along an elongated spike (20-40 cm long) at the tips of the stems. The flowers are brick-red or salmon-pink coloured and have six fused petals. They are sessile, subtended by small leafy bracts (15-25 mm long), and are quite widely spaced along the spike (about 3-4 cm apart). Each flower also has three stamens, with purplish anthers (about 10 mm long), and an ovary topped with a three-branched style, with each style branch being forked again near its tip.
Fruit (i.e. capsules) and seeds are not produced in New Zealand, instead, clusters of small reproductive structures (known as cormils or bulbils) are produced at the upper stem joints (i.e. nodes). These 'bulbils' are reddish-brown or brown in colour (10-25 mm long and 5-7 mm across), shiny in appearance, and have a short curved beak. Four to sixteen of these 'bulbils' are produced in each cluster.
Watsonia reproduces vegetatively via underground 'bulbs' (i.e. corms) and smaller 'bulbs' (i.e. bulbils or cormils) on the stems. The underground corms (4-8 cm across) sprout 1-3 new smaller 'bulbs' during each season, which readily become detached from the parent corm. Corms may be dispersed during soil moving activities, by water, and in dumped garden waste. 
The environmental impact of Watsonia is that it creates a large fibrous matt environment where native seedlings cannot get a hold. Dense infestations can cause silt to accumulate on alluvial sites, leading to flooding or changes in habitat.