Wisconsin Wildflowers: Stellaria
Stellaria: Stitchwort, Starwort & Chickweed
Stellaria L. [Stitchwort] Low, spreading or erect perennials… mostly glabrous; stems slender, 4-angled. Flowers solitary in forks of the stem or in rather sparsely flowered terminal cymes; pedicels filiform. Sepals green with scarious margins; petals white, bilobed to deeply cleft; stamens 10 or sometimes fewer; carpels 3, styles 3. Fruit an ovoid or oblong capsule, laterally dehiscent by 6 valves. - USGS Northern Prairie Wildlife Research Center - Stellaria Genus
Stellaria borealis, graminea, longifolia, & longipes Goldie et al
Stellaria borealis, graminea, longifolia & longipes Goldie - So what's in a name? Okay, how about Stellaria crassifolia, Stellaria holostea and Stellaria media? Now add Stellaria aquatica and Stellaria palustris. But before we're done, let's get technical Stellaria borealis ssp. borealis and Stellaria longifolia var. atrata and Stellaria longifolia var. longifolia need to be added to the list. Now we have all 11 out of 11 total Wisconsin taxa of the genus Stellaria.
Again I ask: What's in a name? A lot! The genus name Stellaria is easy enough. It comes from the shape and color of the flower as well as the sheer profusion of blossoms shared by the 31 species and 43 accepted taxa. Star-like, or stellar, justifiably describes the numerous small white flowers and massed presentation common to the genus.
In a number of Stellaria species, notably borealis, graminea, and longifolia, individual plants are decumbent in nature, often relying on surrounding plant growth to help support the sometimes wildly branching flower stems. Commonly appearing en masse, it is often difficult to determine where one plant starts and another ends. Due to the branching nature of the flower stems, the flowers that appear over one plant may belong to another. In larger groupings, the resulting growth resembles nothing less than a tangled mass and a virtual galaxy of stars.
Stellaria Identification - sometimes a great challenge…
Of the eleven species, subspecies and varieties of Stellaria found in Wisconsin, six are native in origin while the remaining five are naturalized plants introduced from Europe. Identification is not always easy, in fact a sampling of photographs and illustrations (found on the Web), of individual species, reveal a noticeable disparity. Features noted as identifiable characteristics of one type often do not match other examples. In some cases misidentification may be the cause, but interestingly enough, there may be another reason for the incongruity.
Stellaria identification issues may be compounded by site specific growth habits as well as regional variations. A lack of photographic specimens of various species only compounds the issue. In any case, it reinforces the care needed for proper identification. While some species of Stellaria are relatively common throughout Wisconsin, others such as Stellaria longipes Goldie and Stellaria holostea are not, and as such, proper identification of these species is not always a given.
Criteria offered for Stellaria species identification focuses on key characteristics such as leaf shape (oblate, lanceolate and oblanceolate), growth habit (upright, decumbent or sprawling), and flower characteristics (petal length versus sepal length, petal cleft and carriage). Can regional and site specfic conditions cause significant growth variations, substantial enough to complicate simple species identification? Dr. Chinnappa of the University of Calgary is involved in an interesting study on environmental effects on the growth habits of Stellaria longipes. The implications point to the adaptability in growth habits dependent on particular environmental conditions.
STUDIES ON PHENOTYPIC PLASTICITY IN STELLARIA LONGIPES (CARYOPHYLLACEAE): "Evolutionary biologists and ecologists use the term phenotypic plasticity to describe the ability of an organism to alter its physiology, morphology or development in response to changes in environment. Understanding the mechanisms through which perception of critical aspects of environment is translated into changes in growth and development is vital in assessing the ecological significance of plasticity.
"Plants usually respond to environmental signals by releasing hormones which in turn can act as endogenous signals that initiate many physiological responses down stream. Hormones can play a key role as mediators in transduction chains and thus can be involved in the regulation of environment-induced plant responses such as timing and phenotypic plasticity." - Dr. C.C.Chinnappa [ http://www.stellaria.net/ ]
Stellaria native plants and naturalized introduced species
There are eleven known Stellaria taxa resident in the State of Wisconsin. The following lists natives and naturalized plants.
- Stellaria borealis Bigelow ssp. borealis [native]
- Stellaria crassifolia Ehrh. [native]
- Stellaria longifolia Muhl. ex Willd. [native]
- Stellaria longifolia Muhl. ex Willd. var. longifolia [native]
- Stellaria longifolia Muhl. ex Willd. var. atrata J.W.Moore [native]
- Stellaria longipes Goldie [native - endangered]
- Stellaria aquatica (L.) Scop. [naturalized]
- Stellaria graminea L. [naturalized]
- Stellaria holostea L. [naturalized]
- Stellaria media (L.) Vill. [naturalized]
- Stellaria palustris Retz. [naturalized]
Caryophyllaceae - The Pink Family
The Stellaria Genus belongs to the Pink Family - Caryophyllaceae: Annual or perennial herbs, often with a sticky, glandular pubescence. Leaves simple, opposite, sessile, entire, usually exstipulate. Flowers perfect, regular, solitary in forks of the stem or in terminal cymes; sepals 5; petals 5, often reduced or absent, often bilobed or deeply cleft, white or pinkish; stamens usually numbering the same or twice the number of the sepals, sometimes fewer; pistil 3- or 5-carpellary, styles 3 or 5, ovary superior, 1-celled. Fruit a many-seeded capsule, dehiscent by valves or terminally by teeth. Classification for Kingdom Plantae Down to Family Caryophyllaceae. Integrated Taxonomic Information System [ITIS] Caryophyllaceae Taxonomic Serial No.: 19942
Wildflowers and waterfalls: nature's own designs graphics tutorials
Water falls are beautiful. Not far north of Land O' Lakes, just outside of Paulding Michigan, is one the Upper Peninsula's spectacular waterfalls, Bond Falls. It is also the inspiration for IntimatExpression's wonderful and easy to follow, Janim Lake Applet Tutorial - Enjoy!
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