Ornamental Plant for ID : Delhi : 181212 : AK-1: A cultivated, ornamental plant seen in a garden in Delhi on 6/12/12.
looks like yucca
If the leaf end is not needle sharp and is soft to touch, its Yucca desmetiana
best pics and discussions is at: http://www.palmtalk.org/forum/index.php?showtopic=34165
the forum members at this palm talk dot org are all good gardeners and I find they are very friendly.
enjoy their give and take and diagnosis almost at the bottom of their pages, I like their photos too…
Many thanks for the id.