The book 'Food Plants of China' by Shiu-ying Hu reports that peasants extract edible starch from the bulbs of Cardiocrinum giganteum (var yunnanense).
By contrast 'Mansfeld's Encyclopedia of Agricultural and Horticultural Crops' states the starchy bulbs are actually used as vegetables.
I decided to eat some bulbs to see for myself, is it a convenient vegetable or purely a starch source?
As I suspected the outer layers (scales) of the large bulb I tried were very starchy but too fibrous to eat directly as vegetables, so would only be suitable for starch extraction (I only tried a large fully developed bulb, it is possible the smaller young bulbs are free of fibers). The inner core however, when peeled, is free of fibers and has a pleasant texture, like more widely eaten Lilium bulbs, so is, in my opinion, suitable for use as a vegetable. It is however slightly bitter and you do not get a huge amount to eat compared to the very large space this plant takes up. It looks like it would be considerably more productive as a starch source than as a vegetable, the numerous fibrous outer scales for starch, the comparatively small core as a vegetable.
The fact that it takes around seven years to reach maturity (then dies sending out offshoots) may also indicate it is not a particularly productive crop, especially if you don't have much space.
Despite possible drawbacks this plant may still be one of the better understory crops around since it is reportedly tolerant of deep shade and dry soil (Ref: The Genus Cardiocrinum. Philip Bolt http://www.redhall.org.uk/GardenOpening/cardio_bklet.pdf.) I'm trying it out under native and exotic trees at present.
