by Pat Jaquith
Finding Treasures in the Mud of Owen Sowerwine Natural Area
Making a list of plant species in Owen Sowerwine seemed like an easy enough task in September when the trails were dry, vegetation was senescing, and the deciduous trees still had leaves and fruit, so I accepted the challenge and started out. Seasons progressed, and I realized that I hadn’t seen what was growing there in June. I drove down Treasure Lane and set off — but not too far! I got as far as the slough, where the ferryman wasn’t waiting to transport the uninitiated across a full channel, and turned back. This newcomer has a daunting amount of homework to do on the assignment in this wetland!
On August 11, 2022, after a rainy spring when the slough flooded to a depth of 8 or more feet (as estimated from the silt that still coated the vegetation) and lasted well into July, I stocked up on mosquito repellent and ventured into the slough again. WOW! I had not gone far when a “lifer” plant popped out at me among the dense grassy vegetation! On hands and knees in the mud, I investigated the slender plant with tubular lavender blossoms from every angle, took photographs galore and measured as many features as seemed useful. With my hand lens I examined the square stems, counted the stamens in the tubular flowers, and observed the pattern of seeds developing from the senescent blooms. I counted the number of plants in that area. Did I miss anything? All this information went home with me to begin my homework! I returned to the site and double-checked. Eventually, I had a tentative identification: Physostegia parviflora, Purple Dragon-head, as it is cataloged in the Montana Natural Heritage Program. It is a member of the Lamiaceae/Mint family. Its Wetland plant indicator status is FACW (67-99% of occurrences are in wetlands).
The same day, before I recovered from the excitement of finding a “lifer”, I discovered a patch of Lysimachia ciliata (Fringed Loosestrife) plants. Though new to me in Montana, I had some familiarity from New England. Its five bright yellow pointed petals on the 6 to 8 inch plants are a lovely sight – but what about the “fringe”? Down on hands and knees in the mud again! Get out the hand lens. Look at the silt still adhering to those little stems! They had been flooded up to their necks! There it is: the fringe is a collection of little erect hairs in the intersection of the leaf and stem!
Fueled by the elation of finding two great plants, I continued on. My final discovery for the day was a mixed blessing. I’d located a second lifer, but it bore such a strong resemblance to a well-known aggressively invasive wetland plant, I had my worries. Pictures, measurements, pawing through the vegetation, more mud…I took my data and went home to do the research. Indeed, Lysimachia vulgaris (Common Loosestrife) is a non-native that has a reputation of becoming invasive.
Below are partial lists of wetland plants that I have cataloged in OSNA. Some of the plants in Owen Sowerwine are in the “Obligate Wetland” category (99% of occurrences are in wetlands). Bladderwort (Utricularia); Silverweed (Potentilla anserina); Northern arrow-head (Sagittaria cuneata); Hooded skullcap (Scutellaria galericulata); Mare’s tail (Hippurus vulgaris); Sandbar willow (Salix exigua); Beaked sedge (Carex rostrata); Least spikerush (Eleocharis acicularis) and Northern water-plantain (Alisma triviale). Many of these grow in pools or frequently-flooded areas.
Among the native plants in the category “Facultative Wetland” (67-99% occurrences in wetlands) are Hippurus (Common mare’s tail; Marsh hedge-nettle (Stachys palustris); Twisted stalk (Streptopus amplexifolius); Field mint (Mentha arvensis); Sneezeweed (Helenium autumnale); Stinging nettle (Urtica dioica); and Small yellow water-buttercup (Ranunculus gmellini); Alder (Alnus incana); and Poison ivy (Toxicodendron Rydbergii).
Non-native plants in the “Facultative Wetland” category include Creeping buttercup (Ranunculus repens); Reed canary grass (Phalaris arundinacea); Common loosestrife (Lysimachia vulgaris); Black medic (Medicago lupulina); and Redtop (Agrostis alba).
Owen Sowerwine Natural Area is a vulnerable location. The rich, moist bottomland of the Flathead valley provides a perfect spot for plants to get established. Birds help distribute the seeds. The floodwaters scour upland areas and provide transportation. Its proximity to human activity can be a source of those seeds, as gardens and farms have long been a part of this valley. Awareness and vigilance are going to be required to keep the Natural Area “Natural.”