A bit of the devil in it, to keep the devil off it

In a world ruled by natural selection, plants have evolved many methods to escape being eaten by herbivores. These little tricks take many forms, from poisons like deadly nightshade, to spikes on cacti. At the U of M Conservatory Greenhouse I've noticed one particular plant that displays an unusual trick to fool animals that would otherwise eat it in its youth.

The leaves of the juvenile lancewood plant from New Zealand are about as photogenic as they are appetizing -- in other words, not at all! The serrated leaves are stiff and barbed. They also appear to be dead, with a desiccated brownish color. But as the plant grows taller, up to 60 feet, it completely changes its form of its leaves, and the trunk grows multiple branches forming a lollipop shaped canopy.

The tender green leaves of the mature tree appear similar to eucalyptus leaves, with smooth edges. These tender mature leaves are well above the reach of grazing animals like the giant 12-ft moa bird that roamed New Zealand before human settlement. This rare bird likely drove the evolution of this plant.

Serrated leaves of the immature Pseudopanax ferox (toothed lancewood tree)

Unphotogenic and appearing to be dead, this youngster will change its shape

On the New Zealand trail: mature to the left, juvenile to the right

Native to New Zealand, there are several species of Pseudopanax. They thrive in a moist cool climate. Recently, I had the opportunity to see them in the wild along the trails in New Zealand, and recognized a few different species. Another species, Pseudopanax crassifolius, has leaves with fewer toothed serrations, greener leaves, and red stripes.

This ability to shape-shift as the plant matures is called heteroblastic development. According to Wikipedia the switch from juvenile to mature leaf forms is an age-dependent genetic switch.

Pseudopanax crassifolius (lancewood tree, juvenile leaf)

Comments

Thrip control: peppermint and clove

Here's a question: how many natural plant scents do you find repellent? The one that comes to the top of my mind is the scent of the newly blossomed corpse flower, Amorphophallus titanum . It smells very much like the name implies. If I could produce a scratch-and-sniff blog post, I would be tempted. The odor is horrible to humans, but sweet to some flying insects which are also attracted to rotting flesh. But perhaps you cannot tolerate the scent of clove, or eucalyptus? Insect pests are like us in this respect. Pests in the garden and greenhouse Insects, arachnids, fungi, and viruses. Their numbers are legion. The battle is constant. The most effective weapon is vigilance. In addition to vigilance, there are biological controls made from natural compounds which are generally non-toxic to humans. Included in this category are essential oils. For example cinnamon, rosemary, sage, neem, clove, peppermint and many others. These oils are repellent, and even toxic, to many of the pests...

Remembering my former city garden

This post is more of a journal entry than a public blog post. It is interesting to me, but won't be too interesting to almost any other reader - except perhaps my partner who was there as a co-conspirator. I want to document my thoughts about the past, my backyard garden, and what we put in it. The size of our city lot was not large. At 100 x 50 ft, there was just enough room for the house, a small garage, and back yard. The driveway was shared with our neighbor. The style of the house was standard American Foursquare, built in 1903. We bought the place in the early 1990's and slowly, over the next 25 years, renovated almost every inch the house and garden. A dry stone wall was built, with terrace bed to break up the height of the wall Caladiums and dragon-wing begonias line the steps of the front porch Well-earned sit-down on the front porch after a busy day Front wall terrace with blue phlox, hostas, astilbe, snap dragons, and coral bells. Front wall terrace, brunnera "J...

Nerding out in Japan, autumn of 2025

We celebrated a bit of good news in our household with a spontaneously planned trip to Japan in November. Completely unintended, the trip coincided with the full regalia of fall colors. Particularly notable were the popular Japanese maples of every size and variety with their brilliant reds, yellow, oranges, greens, and rusts. But happy accident, we learned a few things about the art of sculpting full-grown trees - niwaki - and how to protect plants from ice and snow over the winter - yukizuri . Winter is coming The fall colors were still in full swing with crowds of adoring leaf-peepers - like me - filling the famous gardens and parks. Despite the crowds, there was already serious preparations for the coming winter. Fancifully pruned trees - the tree-sculpting art of niwaki similar to bonsai - were being trussed with ropes and propped up on long poles . As newcomers, the preparations seemed extremely odd, as if some hurricane was about to shred the life out of every branch an...

City Gardener

Search This Blog