Though the typical "bulb season" has for most purposes past for most people, a number of bulbs are apexing or just starting to bloom now. Irises are in the spotlight now for many. The native Iris chrysophylla continues to bloom all around the region, though many of the flowers are being obscured by the lightning fast growth of the grasses which are now setting seed (much to the gardeners disdain!) thanks in part to the recent rain. These plants are perfectly adapted to growing with grasses which may in part protect them from browsing deer (as we move towards the dry season, the deer are willing to eat more diverse plants).
|Iris chrysophylla anther and stigmatic lip|
Irises are fascinating plants. They are one of the few plants whose leaves can photosynthesize on both sides, capitalizing on any sunlight that they can capture. The flowers are most fascinating, both from a casual and a botanical point of view. The true petals, or "standards", are often upright or sometimes hanging down (as is sometimes the case with Iris chrysophylla and others). The sepals are called the "falls" and are usually hanging down, often with intricate veining and nectar guides. The reproductive parts and pollination ecology are the most interesting aspects to me. Every Iris flower (as well as a few related genera, Morea for example) is separated into three symmetrical sections. Each section has an anther and a part of the modified, flattened stigma. The stigma is modified into three petal-like arms, which often share the color of the tepals.
Being bee pollinated plants, bees are meant to enter one of the chambers and brush its back on the anthers. Upon visiting the next flower, the bee will inadvertently scrape its back on the stigmatic lip before contacting the anther, depositing the pollen and possibly facilitating pollination. While this is ideal, some bees, often small bees that aren't the main pollinator of the species, will bypass the anthers and stigma altogether and go in from the side for the nectar. This is probably most often the case with non-native irises, either invaders or garden plants.
|Iris × germanica 'Wabash'|
This plant has an interesting history, both in the world and in my garden. Iris germanica 'Wabash' is an old favorite, having been introduced in 1936 and winning numerous awards for its simple yet beautiful and delicate flowers. In my garden, it has grown as a group of non-flowering plants in dry shade for over six years. Two Autumns ago, I finally broke up the neglected rhizomes and transplanted them to various sunnier locations. The part of the rhizome in the middle of the clump had no growth on it, and pretty much every resource on Iris maintenance says to discard this center section. Being the curious gardener I thought "What the hell, why not?" and planted the dead looking sections in the finest soil in a nearby raised bed. A year passed with no growth, until last fall when I noticed some leaf growth coming from what I thought should have been rotted remains of the rhizomes. Then a week ago, to my utter surprise, these flowers appeared! The funny thing is that this and another "I thought it was dead" section are outperforming all the other divisions!
|Iris × germanica 'Wabash' beard and stigmatic lip|
Iris × germanica is believed to be a natural hybrid from Germany, rather than a true species. It is one of the most common irises in cultivation, sold almost everywhere as a rhizome cutting in the fall along with Spring flowering bulbs.
|Iris pseudacorus anther and stigmatic lip|
A view inside one of the three chambers, the long anther and the stigmatic lip are visible. The style arm protects the anther and the pollen from washing away in the case of rain. Also there are some solitary bees which are said to take night refuge inside some species of Iris flowers, possibly serving as true pollinators to them as well.
|Iris pseudacorus and a small wasp attaining nectar|
I was lucky to see this small wasp obtaining nectar from this flower. This illustrates the point I made above of how small floral visitors to irises will bypass the reproductive organs altogether to get to the nectar. Wasps do not collect pollen intentionally, and this wasp would have nothing to gain from moving higher up to where the anther or stigmatic lip reside. If I had to guess I would say bumblebees or other large bees would be the most efficient pollinators of this species.
Here the yellow flag is growing in a moist roadside ditch. The plants reach over three feet tall, some said to grow as tall as five feet! Being alongside a country highway between Grants Pass and Rogue River with cars rushing by at around 50 mph, the flowers still put on a colorful show and are highly visible to the passer-by.
An Iris relative in my garden is blue-eyed grass, Sisyrinchium bellum. The plants have iris-like leaves forming a grass-like open mound, these small (around an inch across) flowers at the ends of longish scapes. Though they may not be considered "showy", I still find the plants to be highly attractive. They are native to the West Coast, from California north into Oregon and beyond. I have never seen any floral visitors to these flowers, though I have read they do not attract their pollinators with pollen or nectar but instead by floral oils which are probably excreted at the base of the flower on warm days. Floral oils are produced by many genera in the Iridaceae (Iris family) to entice oil collecting bees to visit them and pollinate their flowers. I speculate that the flowers have some sort of self-pollinating mechanism, perhaps late-acting, to ensure reproduction since the seed pods are always packed full of seed.
These small wildflowers, easily missed if you are not looking for them, are coming into bloom now here. Dichelostemma congestum is very similar to D. capitatum and can be differentiated by the shape of the appendages surrounding the reproductive parts in the center. In this species, the appendages are forked (thus the common name, fork-toothed ookow) while in D. capitatum the appendages are slightly rounded. The corms were used as a food by the Native Americans. Deer will also eat them, which may be why they have adapted to grow among tall grasses, setting seed and drying out at this time of year.
Henderson's stars, Triteleia hendersonii, is coming into bloom in some surprisingly shady areas around our home. In my observations, the plants do not seem to grow in areas that receive the full Summer sun, instead preferring the edges of clearings, sometimes where there is little competition. There are only a handful of individuals in the areas I have found them growing. I have wondered if they once grew in masses here, but have since retreated to their current locations after decades of mowing and development by humans and deer herbivory.
|Allium amplectens 'Graceful'|
This is a nice onion, flowering well in the variety of locations that I have planted it in. It has done better in the sunny sites, though the true test of the growing success of bulbs is time. Alliums, like other true bulbs, form the next years buds this year so in essence their success depends on good conditions in two-year blocks, overlapping of course. The best growth from bulbs may be attained from two consecutive years of ideal conditions, the first year to form the buds, the next to flower them, and so on and so forth.
This tiny onion packs a punch, the umbels proportionately larger than the plants themselves. I plan on growing many more of these in the future, from acquiring new bulbs to collecting the seed from my plants.
Last year I witnessed a single beetle on this plant which literally remained on the inflorescence for several days feeding on the pollen. I have not seen anything on these flowers yet this year.
False Solomon's seal, Maianthemum racemosum, is a forest dweller with an international distribution. I recently found a small patch in a neighbors yard, a proud discovery for me (though it's just another plant for him). I guess not everyone has the same unhealthy obsession with plants as I do!