Like last week’s Philesia magellanica, today’s species is also a member of a family containing only two species. In this instance, though, both species are within the same genus, Cercidiphyllum.
Douglas Justice, Associate Director of Horticulture and Collections at UBC BG, is responsible for the rest of today’s entry. These are excerpts from the Vancouver Trees app:
A native of temperate eastern China and Japan, Cercidiphyllum japonicum is a fast growing deciduous tree with a broad, rounded crown. The species is particularly valued for its strongly ascending, often multiple stems, attractive, rough bark and tiered, well spaced, sweeping branches. Katsuras are texturally unlike most other trees, growing 20 to 30 m tall with prominent bunches of radiating branches at the ends of main scaffold branches. As well, long-lived short shoots naturally develop along the branches. Each short shoot bears a single leaf in the growing season and extension growth is limited to a few millimetres annually. Much like in ginkgos and larches, the prominence of the short shoots over normal extension shoots increases with age, giving the un-shaded interior branches of mature katsuras a leafy, well-clothed look in summer and a somewhat knobby, but not unattractive appearance in winter.
Cercidiphyllum species are wind-pollinated and dioecious. Leaf emergence is preceded by the opening of hundreds of tiny, scarlet, apetalous flowers on the short shoots that line the mature branches. The finest of spring days start by seeing the flowers catching the morning sun, like so many tiny rubies. On female trees, the fertilized flowers turn into clusters of tiny, up-standing pea-pod-like follicles. Cercidiphyllum is classified in its own family (Cercidiphyllaceae); its closest relatives include species of the Altingiaceae (the sweetgums) and Hamamelidaceae (the witch hazels).
The new leaves of most katsuras emerge copper or bronzy green, although darker red or even purple new foliage is also known, and they are accompanied by thin, caducous stipules. Katsura leaves are ovate to rounded, with a cordate base, not unlike those of Cercis, hence Cercidiphyllum, from kerkis = redbud + phyllon = leaf. They are about 5 to 9 cm across with impressed veins and crenate, recurved margins. The leaves are borne oppositely, or sometimes sub-oppositely, along the long, slender shoots. Those produced from short shoots are usually larger and more rounded. The leaves are exceptionally waxy, often glaucous below and dull above, shedding rain in rivers of beads. The dull leaf waxiness seems to enhance the absorption and transmission of light through the canopy, rather than reflecting it away. In autumn, the leaves glow in modest fiery tones of yellow, coral pink, red and black purple, usually a branch at a time, although shaded plants typically turn pale translucent yellow. If that wasn’t enough to recommend the genus, the senescing leaves of katsuras smell of burnt sugar—strawberries, ripe apples or candy-floss to some—a deliciously pervasive fragrance around any specimen in autumn, as well as during prolonged summer droughts.
The tall, elegant weeping katsura, Cercidiphyllum japonicum ‘Morioka Weeping’, has strongly upright primary shoots and pendulous side branches (essentially, an excurrent habit). Plants can become tall and wide spreading (10 × 7 m after 25 years), with several upright stems and numerous gracefully cascading branches, not unlike a narrow weeping beech. ‘Morioka Weeping’ is an ancient Japanese clone known from before 1635, but modern stocks are all derived from an individual plant collected at the Ryugenzi Temple near the city of Morioka in northern Japan. It is often listed in the trade incorrectly under the name Cercidiphyllum magnificum ‘Pendulum’, but it is definitely a Cercidiphyllum japonicum cultivar. ‘Morioka Weeping’ is a staminate (hence, seedless) cultivar.
I should note that this photo was taken 5 years ago to the day. I suspect this plant doesn’t look quite as leafed out today, given the overall cooler spring.
Thank you Daniel and Douglas
So good to have Botany Photo of the Day back up and running.
Today’s image itself perfectly calming and soothing to look at during these taxing
times.
Brings back happy memories of my days at UBC Botanical Garden
I have happy memories also……of my FOG days barely 2 weeks ago.
A cercidiphyllum came up in my garden 12 years ago as a volunteer. Spread by a bird? It was in a tight outer corner of a porch and almost up against a sidewalk. But I didn’t know who she was at the time and that she wanted to grow 60 to 90 feet tall! So I left her. Three or four times a summer I need to cut back the vigorous growth to keep her within her allowed space. Each season the trunk gets thicker but the height has to stay at five feet. I leave the trimmings on the ground and am rewarded with the scent of cotton candy from the dry leaves crunched under foot all season, not just in fall. The weeping habit of the branches is noticeable and endearing.
Beautiful tree. How is the name pronounced?
Good question! Depends on who you ask, but I suggest most people would use a “S” sound for the “c”s in the name.
After that, I am leaning toward the more mellifluous way of saying scientific names these days, but I am sure there are others who inflect the second syllable.
I generally think Italian and wave my hands about expressively to get the right rhythm.
As it comes from the Greek, traditionalists would use a hard c for both, kerKIdi-FILLum. Though hardly anyone nowadays pronounces the p in Psammophila or Pseudabutilon. The Greeks would not have had a letter psi if it was the same as an s.
The hyphen looks like the word was too long to fit on the line. So, just to make it clear, the word is made up of two elements Cercidi- meaning like a Cercis and -phyllum meaning leaf. I would usually emphasise that they are two elements like you would with gingerbread.
What a glorious pic.
Thanks as always.
So beautifully described! I did not know the leaves were especially waxy, I’ve never noticed that, and love how you described the shedding of “beads of rain.”
Near where I live in Queens are a few mature katsuras on the site of the old Parsons Nursery, making them likely the first or among in the US. I thought the species was actually subopposite most of the time, another rare trait.
I don’t think I’ve ever seen a weeping form, it must be so glorious. Thank you both.
Glorious image, Daniel. And one of my favored trees.
To this layman deep in TX I appreciate you appearing in my inbox so I can see more of this world of nature.
Sometimes its nice to get a picture of something before it reaches its peak in the garden. That way one gets an alert and has time to plan to view. That is of course if one is not an ocean away…
In a study done by Hilliers and Iowa State University it was found that all of the weeping forms of Cercidiphyllm japonicum are “males” . To date there has been no discovery of weeping forms with female flowers . Curious
Perhaps there is an advantage to lofting the pollen into the air from flexible hanging branches that whip in the wind. The receptive female flowers probably have more advantage from being held up high in the air.
A little quibble – the ancient Greek kerkis (κερκίς) was, of course, the Old World Judas tree, Cercis siliquastrum. Redbud is a North American name for the American trees. “European redbud” is wrong on two counts, the tree is native to the Northern Mediterranean coasts in Europe but also Turkey, Lebanon, Syria and Iran. That would be like calling Cercis canadensis the New Jersey redbud.
Perhaps three counts, as I have seen white, lavender and pinky-purple flowers on the Judas tree but not any I would call red.
Thank you for a very graceful photograph, Daniel. I always enjoy seeing Katsuras planted on the street and I think it IS the structure that’s so pleasing. I didn’t know about the burnt sugar smell to crushed fall leaves. The subtle joy that emanates from the text is wonderful, too.
Beautiful photo. I love Katsuras and wonder if there is such a thing as a Dwarf Marioka Weeping?