Cardiocrinum is a small genus in the Liliaceae family whose members are distributed from northern India to Japan. Three species are in cultivation. Cardiocrinum giganteum has been well established in cultivation in England for well over a century. Given the rarity of these plants in eastern North American gardens, it's hard to believe, but Peter Hanson grew C. giganteum in Brooklyn, New York, USA during the second half of the nineteenth century. Although originally introduced long ago, C. cordatum and C. cathayanum have only recently become readily available.

Generations of writers have repeated the incorrect notion that these plants are monocarpic. They are not monocarpic. Yes, the flowering stems die after seed set; in fact, they die whether seed is set or not. But so do the fruiting stems of tulips, lilies, fritillaries and a host of other similar plants. The perennial stem (i.e. the basal plate) and its offset bulbs live on from year to year.

A relaxed approach used by Stephen J. Vinisky to germinating seeds is to sow them in a 5 1/2 inch "azalea" pot. He uses a 1/3 grit mixture. The pot size holds about 18 seeds comfortably. After sowing on the surface of the firmed mix, top the seeds with 1/4" of chicken grit. The pots go outside (under the eaves of the house in a shady, eastern exposure to keep off the majority of our almost continuous rain) and are subject to whatever the winter weather provides. In late spring, the seeds put up one very tiny leaf that attracts every slug and snail for miles around. Sluggo is a less toxic way to effectively keep slugs away.

A more active approach is to sow seeds in good potting mix, water and place in a plastic bag at 55-65 °F (13-18 °C) for 2-3 weeks. Then place in the fridge to stratify for 4-6 weeks and return to germination temperature. Remove from the plastic bag and keep the mix moist. Germination can be very slow.

Transplant seedlings when they're large enough to handle. Both seedlings and adults should be grown in part sun with plenty of moist and organic rich soils (much like conditions for growing hostas). A little fertilizer is recommended during the growing season.

Fresh Cardiocrinum seed has underdeveloped embryos, and a temperature cycle is required before these embryos develop to the point where the seed can germinate. If seeds don't have developed embryos they won't germinate soon.

Research Post-dispersal embryo development, germination phenology and seed dormancy... American Journal of Botany 93(6): 849–859. 2006 shows that seed given a spell of warm 25°/15 °C, developed embryos at 15°/5 °C, which after a period of stratification at 0°–5°C, started to grow at 5°–15°C. "Seeds that have an underdeveloped embryo at the time of dispersal and require specific temperature conditions for embryo development and radicle and cotyledon emergence have morphophysiological dormancy (MPD)". See also Fritillaria Germination. In other words, seeds require the heat of summer followed by the cool of fall to develop embryos. Exposed to the natural temperature cycle they will often, as in nature, take over a year to germinate as they first wait for high temperatures and then low ones.

The photographs below by David Pilling show what fresh seeds and seeds with developed embryos look like.

The first set are of fresh seed using reflected light and on a 10 mm grid.

Cardiocrinum giganteum var. yunnanense seed, transmitted light, David PillingCardiocrinum cordatum seed, transmitted light, David PillingCardiocrinum giganteum seed, transmitted light, David Pilling

The second set are of the same seeds using transmitted light, it is apparent they have no large visible embryos, however the undeveloped embryo is visible.

Cardiocrinum giganteum var. yunnanense seed transmitted light, David PillingCardiocrinum cordatum seed transmitted light, David PillingCardiocrinum giganteum seed 9th January 2013 transmitted light, David Pilling

The idea was to show how embryos develop over time when the seeds are exposed to moisture and changing temperatures, however all the seed in the first two photos rotted, although all of that in the third photo developed embryos. This first photo shows one seed from the third photo, using reflected and transmitted light at the start of January 2013 and at the end of February 2014. Deciding if seed is viable from the sort of photographs above is problematic, could one look at the three photos and decide which was the good packet of seed. The second photo shows another seed from this batch using transmitted infra-red light which makes the embryo easier to see. Photo 3 uses a dark field transmitted visible light technique.

Cardiocrinum giganteum seed, reflected and transmitted light 9th January 2013 and 26th February 2014, David PillingCardiocrinum giganteum seed, transmitted infra-red light 3rd March 2014, David PillingCardiocrinum giganteum seed, transmitted visible light 25th March 2014, David Pilling

The next two photos show a seed that has been kept moist through Summer and Winter and has developed an embryo; photo 1 reflected light, photo 2 transmitted.

Cardiocrinum cordatum seed with developed embryo, reflected light, David PillingCardiocrinum cordatum seed with developed embryo, transmitted light, David Pilling

Cardiocrinum cathayanum is from China, described by E. H. Wilson in 1925. Photographs by Pontus Wallstén, who comments "I find that C. yunnanense tends to have bronze or purplish leaves on emergence, which eventually turn a nice lime green, while C. cathayanum mainly tends to be lime green already on emergence". Compare the bulb image with that of Cardiocrinum giganteum var. yunnanense below.

Cardiocrinum cathayanum bulb, Pontus WallsténCardiocrinum cathayanum bulb, Pontus WallsténCardiocrinum cathayanum bulb, Pontus WallsténCardiocrinum cathayanum bulb, Pontus Wallstén

Cardiocrinum cordatum -- The two photos below show two phases in the life of the species photographed in the garden of Jim McKenney. The plant shown first bloomed in July, 2000, and is now about to bloom again in 2004. The first photo shows the foliage as it appears in early spring. Freezes are still common when this foliage starts to grow, but so far cold damage has not been observed here. Plants not vigorous enough to bloom remain at this stage all season. At this stage they resemble skunk cabbage:

Cardiocrinum cordatum, Jim McKenney

The second photo shows the plant with its two stems about a month later. At this time, the annual stems have elongated, raising the whorl of foliage well above the ground. This is the "hosta on a stick" phase. The plants remain like this for weeks, seemingly inactive. But if you look carefully at the center of the leaf whorl, you will see the slowly differentiating inflorescence. The inflorescence may eventually extend upward another two or three feet. Here is the "hosta on a stick" phase:

Cardiocrinum cordatum, Jim McKenney

Here are three photos of the same plant blooming on July 25, 2004. Now that the plant is in bloom and getting attention, its identity has come into question. This plant seems to answer to Cardiocrinum cordatum var. glehnii although the Kew Monocots checklist does not recognize this variety. The first photo shows a fully developed bud, the next photo shows the interior or the flower, and the third photo shows two blooming stems. Photo four is by Mari Kitama of var. glehnii in Japan. Photo 5 by Pontus Wallstén is of a bulb a year or two away from flowering size.

Cardiocrinum cordatum glehnii, Jim McKenneyCardiocrinum cordatum glehnii, Jim McKenneyCardiocrinum cordatum glehnii, Jim McKenneyCardiocrinum cordatum glehnii, Mari KitamaCardiocrinum cordatum glehnii bulb, Pontus Wallstén

Cardiocrinum giganteum is native to the Himalayas east to Myanmar (Burma) and China. Photos 1-2 were taken by Jane McGary in northwestern Oregon of plants originating from a Chadwell collection in the early 1990s. Planted in rich humus soil and well fertilized, the original bulbs have produced a series of offsets with flowers most years, beginning 5 years after sowing. This species is intolerant of hot, sunny exposures, where the foliage is liable to burn. Photos 3-4 taken by Nhu Nguyen at the UC Botanical Garden show the seed pods and seeds of this species. Photo 5 by Pontus Wallstén shows a flowering size bulb.

Cardiocrinum giganteum, Jane McGaryCardiocrinum giganteum, Jane McGaryCardiocrinum giganteum, Nhu NguyenCardiocrinum giganteum, Nhu NguyenCardiocrinum giganteum bulb, Pontus Wallstén

Growing in New Jersey for three years. Each year the size and number of leaves increases and soon a flower. Has some offsets that have sent up a single leaf this year. This plant has produced a stalk. The following images taken by Arnold Trachtenberg will show periodic changes.

Cardiocrinum giganteum - May 17, 2005, Arnold TrachtenbergCardiocrinum giganteum - May 28, 2005, Arnold TrachtenbergCardiocrinum giganteum - June 11, 2005, Arnold TrachtenbergCardiocrinum giganteum - June 11, 2005, Arnold TrachtenbergCardiocrinum giganteum - June 14, 2005, Arnold TrachtenbergCardiocrinum giganteum - June 18, 2005, Arnold Trachtenberg

Cardiocrinum giganteum var. yunnanense is native to Yunnan province of China and northwestern Myanmar (Burma). The first three photos below were taken by Nhu Nguyen at the UC Botanical Garden. Photo 4 is by Pontus Wallstén who comments "I find that yunnanense bulbs are usually dark brown or purplish in colour, while C. cathayanum bulbs tend to be more light brown". You can see the difference with the Cardiocrinum cathayanum bulb image above.

Cardiocrinum giganteum var. yunnanense, Nhu NguyenCardiocrinum giganteum var. yunnanense, Nhu NguyenCardiocrinum giganteum var. yunnanense,  Nhu NguyenCardiocrinum giganteum var. yunnanense bulb, Pontus Wallstén

Major reference works covering Cardiocrinum include

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Page last modified on March 27, 2014, at 07:59 PM