(ah-MOR-foe-phal-us ti-TAN-um)

General Information:

The Titan arum - the largest, smelliest flower in the world.

This is not a plant for your garden, but it is a very fascinating plant. It originates in the rainforests of Sumatra and is now grown at many of the larger botanical gardens. I recently had a chance to see it in flower at the University of Guelph which has 4 mature plants.

Amorphophalus titanum; photo by Robert Pavlis

The name Amorphophalus titanum translates loosely to “giant misshapen penis”. It’s common names include Titan arum and corpse flower.

The plant is a tuber (or corm, experts don't agree) that sends up a single leaf structure which can be 6 meters (20 ft) tall and 5 meters (16 ft) across. The first plant to flower in Guelph was grown from seed by Rodger Tschanz and took 11 years to flower.

The flower has the typical arum look with a green/reddish spathe and a tan coloured spadix coming out of the center. The flower can be 9 feet tall and 3 feet wide. The so called flower is actually not a true flower, but if we consider it a flower it is the largest unbranched inflorescent in the world. The flowers are actually relatively small and are located at the bottom of the spadix.

Amorphophalus titanum; photo by Robert Pavlis

In the wild the plant flowers about every 3 years with the male flowers opening a day after the female flowers to ensure that cross pollination takes place. To make this happen the plant needs to attract pollinators from a long distance, and it has a special way to accomplish this. Firstly, it sends out a very strong foul smelling sent that attracts flies and some bees. Secondly, it heats up the spadix to vapourize the odours which makes the sent even more powerful.

Amorphophalus titanum (male flowers in the center, female at the bottom); photo from Wikipedia

The heat generating spadix (thermogenesis) is what makes this plant so interesting. We measured the temperature at 3:00 pm on the day these pictures were taken. The bottom of the plant was 24 C and the top of the spadix was 39 C. How does a plant produce such a large amount of heat? Scientists are still trying to understand this, but it seems that other arums use a chemical reaction that is similar to the one animals use to generate body heat. You could say that the arums are ‘warm blooded’ – not a completely true statement, but a close analogy.

The plants seem be fairly easy to grow in a greenhouse if you have the patience and space.

Life Cycle: perennial

Height: 6 meters (20 ft)

Bloom Time: any time

Natural Range: Sumatra

Habitat: rainforests, steep hills

Synonyms: none

Cultivation:

Light: full sun summer, shade in winter

Soil: 80 % peat

Water: water only when growing, dry when dormant

USDA Hardiness Zone: tropical

Propagation: seed

Seedex availability (ORG&HPS annual Seed Exchange): never  

 (AL-ee-um thun-BERG-ee-eye)

General Information:

The last plant to start flowering in my zone 5 garden is  Allium thunbergii ‘Ozawa’, the Japanese onion. As I write this it is October 26, 2014 and we have not had a real hard frost yet which is very unusual. Most common fall flowering plants like mums are finishing up but the Japanese onion is still going strong. It is not bothered by early frost or snow.

Allium thunbergii ‘Ozawa’; photo by Robert Pavlis

Most alliums flower in spring or summer. This one starts to make buds in early September but does not really open until early October, in most years. It then blooms for many weeks. I suspect the cold fall temperatures keep the buds fresh.

Some alliums spread quickly by seed making them weedy plants, but not this one. It forms a nice clump and rarely self-seeds—probably because the seed does not have time to ripen before winter. In early summer it produces nice grass-like foliage that looks nice all year, developing an orange colour after frost.

Allium thunbergii is also available as a white cultivar.

Allium thunbergii ‘Ozawa’; photo by Robert Pavlis

Life Cycle: bulb/perennial

Height: 30cm (1ft)

Bloom Time: fall

Natural Range: Japan and Korea

Habitat: low mountains, forest margins, slopes and pastures to 1300 m

Synonyms:  none

Cultivation:

Light: full sun to part shade

Soil: well drained

Water: not fussy, drought tolerant

USDA Hardiness Zone: 4– 9

Propagation: seed, division

Seedex availability (ORG&HPS annual Seed Exchange): frequently

 (AL-ee-um  MO-lee)

General Information:

Allium moly is an plant that most people do not recognize as being an onion or garlic. It is short with fairly wide leaves unlike most onions. It also has very vibrant yellow flowers. This great garden plant should be in every garden. It grows just about anywhere, sun, shade, wet or dry – but maybe not in a bog.

Allium moly; photo by Robert Pavlis

Allium moly does not seed around too much, like some alliums, but it does spread slowly. The bulbs are easy to remove in any area where they are not wanted.

The name of this plant is confusing. Both the Encyclopedia of Life and The Plant List, as well as other reliable sources have two species listed; Allium moly and Allium luteum. But in the trade, both species seem to be the same plant. In fact you can find plants named as Allium moly ‘luteum’ or Allium moly luteum. I guess these last names are used by people who are also confused about the name.

To make the naming more interesting, there is a plant described as Allium moly ‘Jeannine’ which was discovered  in 1978 by Antoine and Michael Hoog. This named cultivar is said to be more vigorous, has yellow flowers instead of the yellow-green flowers of the species, and it has two flower spikes per bulb.  All of the bulbs being sold have a very vivid strong yellow colour.  I have purchased the plant under different names, including ‘Jeannine’, and they all seem to be the same.

Allium moly; photo by Robert Pavlis

The Encyclopedia of Life has two accepted pictures which show off-white flowers that could be considered to be yellow-green (http://eol.org/pages/1084730/overview).  I wonder if all bulbs in the trade are in fact Allium moly ‘Jeannine’? 

Common names include; golden garlic, golden onion, yellow flowering onion or lily leek. All parts of the plant can be eaten, but it is not regarded as a good kitchen onion. Some reports say it is quite mild, and others claim that it has a very strong garlic flavor.

Life Cycle: perennial

Height: 30cm (1ft)

Bloom Time: mid June

Natural Range: France and Spain

Habitat: badlands, on mountain ledges and in forest clearings, mainly on calcareous soils

Synonyms:  Allium obliquum

Cultivation:

Light: full sun preferred by grows well in shade

Soil: not fussy

Water: drought tolerant

USDA Hardiness Zone: 3– 8

Propagation: seed, bulb offsets

             Seedex availability (ORG&HPS annual Seed Exchange): usually        

 (AL-ee-um  kar-uh-taw-vee-EN-see)

General Information:

Allium karataviense ‘Ivory Queen’ is a very unusual onion. The leaves are very wide, grow close to the ground and cup a large head of white flowers. Even in flower, the plant is only about 8 inches tall. Common names include kara tau garlic and Turkistan onion.

Allium karataviense ‘Ivory Queen’ :photo by Robert Pavlis

The species has pink flowers while the cultivar ‘Ivory Queen’ is white.  This plant has been in horticulture for a very long time, and I suspect any white flowering form is now called Ivory Queen. After flowering, the leaves slowly wilt and by midsummer the plant goes under ground, to appear again in spring.

Allium karataviense ‘Ivory Queen’ :photo by Robert Pavlis

Pollinators love the flowers and seed is easily produced. These will fall underneath the parent plant and produce grass-like seedlings. If you weed what you think is grass you’ll never have baby plants. Seedlings of Ivory Queen seem to come true and do not revert to the pink wild variety. It should flower from seed  in three years.

Allium karataviense ‘Ivory Queen’ :photo by Robert Pavlis

Life Cycle: perennial bulb

Height: 20 cm (8 in)

Bloom Time: late spring

Natural Range: Central Asia, Karatau Mountians in Kazakhstan

Habitat: loose limestone scree

Synonyms:  none

Cultivation:

Light: full sun

Soil: well drained, sandy

Water: moist while flowering and dry once underground

USDA Hardiness Zone: 4 - 8

Propagation: seed, bulb offsets

Seedex availability (ORG&HPS annual Seed Exchange): frequently