Unknown Backyard Plant, Possibly Introduced

[Wun_Ho]

A colleague has asked me about a monocot that has appeared in her backyard in northern Melbourne, Victoria, Australia. It is likely to be an introduced species, given that it does not resemble any indigenous Asparagales, and that it may be a contaminant in the new garden soil she has recently installed. I have some knowledge of Iridaceae, and I am sure this is not one of them. Any help is appreciated.

[Uli]

Chlorophytum?

[Wun_Ho]

Thank you @Uli for your suggestion. I was entertaining the idea that it might have been a juvenile Agapanthus praecox, which are commonly grown in surburban gardens. I'll admit that the plant in the photos more closely resembles one of the Chlorophytum spp. (I chanced upon a juvenile Agapanthus in the field the day before, and the appearance is quite different.) Flora of Victoria (the State Flora) acknowleges the presence of C. comosum: "Widely cultivated as a house plant, with variegated forms common in cultivation. Both the variegated 'Variegatum' and non-variegated form are naturalised around Melbourne." If my colleague does keep the plant, we can identify it when it flowers.

[Uli]

Hello Wun-Ho,

If it is Chlorophytum it will show typical growth if allowed to grow older and bigger, like plantlets forming on the inflorescences. If you want to wait before disturbing it this will not take long but you could also dig it up and the roots will help identification as well.
Chlorophytum is a fairly weedy plant in my Portuguese garden and I am weeding it in most places because it spreads into smaller plants and overwhelms them after a short period. It might still be something else than Chlorophytum but I would carefully watch it.

Uli