It always amazes me how strong plants can be when they have a huge store of food underground to draw upon.
American skunk-cabbage in 2013
American skunk-cabbage (Lyischiton americanus) produces vivid yellow spathes behind the cylindrical spike of its rather small and insignificant flowers. These appear, with or before the leaves in spring, from underground rhizomes. The plant is a member of the Araceae family, so is related to our native Cuckoo pint (Arum maculatum).
The skunk-cabbage’s natural habitats are marshes and peat bogs in North America. In Britain it will grow happily at the margins of ponds and slow-moving water where it can become invasive. It is pollinated by midges and beetles which are attracted to the skunk-like stink of the flowers.
Two patches of the plant have been growing below the grotto in the wilderness for a number of years – probably a great number of years. During the last couple of winters the Grounds team have been opening up this area and this spring they installed a series of log dams. One of them was placed right over one of the skunk-cabbage patches – probably while the plant was still dormant beneath the ground. Could it survive?
Flowering in adversity
The answer was Yes! It has forced its way up between the logs. It does look a little bedraggled but its flowering!
In many plant genera the same pollination method (or combination of methods) is found in every species. Not so in Acer.
The vast majority of Acer species are insect pollinated. The flowers are strongly scented due to the presence of large amounts of nectar. This is made available to attract insects to crawl around in the flowers and, accidentally, get covered in pollen before flying off to get their next sugar fix – hopefully at another tree of the same species where the pollen will be delivered. Continue reading
White blister rust on Shepherd’s purse
White blister rust is a disease that is mis-named as it is not actually caused by a rust fungus. The perpetrator is an oomycete. This group have traditionally been included in the fungi and have long been studied by mycologists but DNA evidence shows that oomycetes are more closely related to brown algae than to fungi or green plants. It was an oomycete that was responsible for the Irish potato famine in the 1800s.
A single plant of Leucojum aestivum ssp aestivum is flowering near the wooden bridge in the Wilderness. This is the subspecies that is known as the Loddon Lily. Most garden plants belong to ssp pulchellum.
It’s on the bank where alder trees were cut down this winter. Has the extra light enabled it to flower? Or was it just out of sight when there was more growth here?
Is this a leftover from previous planting?
Most fungi prefer warm and moist conditions so it’s not surprising that fungal pathogens are harder to find on plants in winter.
A pathogen that is common on campus at the moment is Puccinia malvacearum, the Hollyhock Rust. This occurs on Malva sylvestris, the Common Mallow.
Symptoms are yellow-orange spots on the upperside of leaves with orange pustules underneath.
Pustules on lower surface of leaf.
Under a hand lens you can see the pustules bursting out from beneath the leaf surface. These are full of teliospores which tend to germinate within the pustule. They grow to produce ash-grey basidiospores which are dispersed on air currents to infect new plants.
Some rust species have up to five types of spores forming a complicated life-cycle but this is not the case with Puccinia malvacearum.
Teliospores with long pedicels
The species is a common disease on hollyhocks, rarely killing plants but causing distorted and stunted growth.
Reading Science Week is here!
The resident exhibition, open from Saturday 15th March and all week, is the Imagining Science Symbiosis Project.
A key member of the Symbiosis project is Immy Smith, an artist and a neuroscientist, with a fascination for biological and surreal imagery.
Immy is currently a visiting artist at University of Reading Herbarium (RNG) which was where Dr M first met Immy and joined her artistic journey around a local lichen twig! Continue reading