Hemerocallis is a very difficult genus taxonomically, with no overall concensus amongst botanists as to how many distinct species there are and the delineation between them. The genus as a whole needs a comprehensive revision. We are trying to follow the most recent thinking for each species, though it is inevitable that a number of species we have included in the genus will have to be amended as and when a comprehensive new treatment is published.

Common Name: Yellow Day Lily

General Information

Hemerocallis lilioasphodelus is a herbaceous perennial plant producing a cluster of stems 70 - 80cm tall from a usually slightly fleshy rootstock[].
The plant is harvested from the wild for use as a food, medicine and source or materials. It is sometimes grown as a food crop in Japan and is often grown as an ornamental, where it can be used as a ground cover.

Known Hazards

Large quantities of the leaves are said to be hallucinogenic. Blanching the leaves removes this hallucinatory component[]. (This report does not make clear what it means by blanching, it could be excluding light from the growing shoots or immersing in boiling water[].)

Botanical References

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Range

Southeast Europe - Italy, Slovenia; Asia - Armenia through central Asia to the Russian Far East, Mongolia, eastern China, Koea

Habitat

Rocky mountain woods, wet meadows and riversides on foothills of the S.E. Alps in Europe[]. Forests, thickets, meadows, grasslands, slopes along valleys; at elevations from 100 - 2,000 metres[].

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Perennial
Height	0.60 m
Pollinators	Insects
Self-fertile	Yes
Cultivation Status	Wild

Cultivation Details

Plants are very cold-hardy, tolerating temperatures down to about -25°c[].
Succeeds in most soils[], including dry ones, preferring a rich moist soil and a sunny position[] but tolerating partial shade[, ]. Plants flower less freely in a shady position though the flowers can last longer in such a position[]. Grows well in heavy clay soils. Succeeds in short grass if the soil is moist[]. Prefers a pH between 6 and 7[].
A very vigorous plant, spreading by underground rhizomes[]. The plant has a fibrous root system with occasional spindle-like swellings[].
Cultivated as a food and medicinal plant in Japan[].
Individual flowers are short-lived, they open in the evening and last for 20 - 76 hours. The plant produces a succession of blooms over a period of about 2 months[]. The flowers are fragrant[]. The flowers have a honeysuckle-like scent and this can pervade the air for a considerable distance when warmed by the summer sunshine[].
Hybridizes freely with other members of this genus[].
Plants take a year or two to become established after being moved[].
Plants seem to be immune to the predations of rabbits[].
The plants are very susceptible to slug and snail damage, the young growth in spring is especially at risk[].

Edible Uses

Leaves and young shoots - raw or cooked like asparagus or celery[, , ]. They must be consumed when very young or else they become fibrous[].

Flower buds - raw or cooked. They taste somewhat like green beans[, ]. They contain about 43mg vitamin C per 100g, 983 IU vitamin A and 3.1% protein[].

Flowers - raw or cooked[, ]. They can be dried and used as a thickener in soups etc[]. If the flowers are picked just as they start to wither they can be used as a condiment[]. The flowers are a traditional food in China where they are steamed and then dried[].

Root - cooked[, ]. They taste like a blend of sweet corn and salsify[]. We have found them to be tender but fairly bland with a slight sweetness[]. The swollen roots are quite small and are only really worthwhile using if the plant is being dug up for divisions or some other reason[].

Medicinal

The juice of the roots is an effective antidote in cases of arsenic poisoning[]. The root also has a folk history of use in the treatment of cancer - extracts from the roots have shown antitumour activity[].
A tea made from the boiled roots is used as a diuretic[].

Agroforestry Uses:

Plants form a spreading clump and are suitable for ground cover when spaced about 45cm apart each way[]. The dead leaves should be left on the ground in the winter to ensure effective cover[].

Other Uses

The tough dried foliage is plaited into cord and used for making footwear[].

Propagation

Seed - sow in the middle of spring in a greenhouse. Germination is usually fairly rapid and good. Prick out the seedlings into individual pots when they are large enough to handle. Grow the plants on for their first winter in a greenhouse and plant out in late spring[].
Division in spring or after flowering in late summer or autumn[]. Division is very quick and easy, succeeding at almost any time of the year[]. Larger clumps can be replanted direct into their permanent positions, though it is best to pot up smaller clumps and grow them on in a cold frame until they are rooting well. Plant them out in the spring.