Kingdom: Plantae
(unranked): Angiosperms
(unranked): Monocots
Order: Asparagales
Family: Iridaceae
Subfamily: Ixioideae
Tribe: Ixieae
Genus: Tritonia
Species: T. gladiolaris
Binominal name: Tritonia gladiolaris
Synonym: Tritonia lineate, Gladiolus lineatus, Ixia gladiolaris
Common name: Lined flame freesia, Chiffon lace, Lined tritonia, Montbretia, Tritonia

Tritonia gladiolaris is a Tritonia genus in the Iridaceae family from the grasslands of southern-eastern Cape of South Africa. It was is cultivated as a garden ornamental but has escaped and it is now a weed of grasslands, roadsides, waste areas and disturbed sites in some of the warmer areas of New Zealand.
Tritonia gladiolaris an upright herbaceous plant usually growing 30-60 cm tall and re-growing each year from long-lived underground ±2 cm diameter corms.
The long leaves are long and strap-like (>35 cm long and >18 mm wide). They have entire margins, pointed tips and three to five prominent parallel veins. They are sheathed at the base.
It has simple or branched inflorescences on the tips of green, hairless, slender, unbranched flowering stems each containing 5-15 flowers. The dull yellow-cream, tubular shaped flowers have six 'petals' with prominent purple or blackish veins. The flower styles are divided into three branches and hence they have three stigmas. sweet-smelling, The flowers give off a very strong fragrance, especially at night. They are not grazed by animals.
After flowering oval fruit capsules (3-8 mm long) form, they turn brown and split open when mature releasing many seeds that are spread by wind and water. Tritonia gladiolaris also reproduces vegetatively via its underground corms. Both seeds and corms are spread in contaminated soil and dumped garden waste.

This Tritonia gladiolaris was growing wild on wasteland in New Plymouth, Taranaki. 
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Thanks to Wikipedia for text and information:https://creativecommons.org/licenses/by-sa/3.0/