Talk:Capsella bursa-pastoris

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copied from commons [1]:

• Shepherd's purse can be found in flower from early spring through early winter. Each flower develops into a heart-shaped, two-celled seedpod, about 5 mm long, containing a number of tiny seeds. When the pod dries, it splits in half, releasing the mature seeds. People have been eating this plant for thousands of years and it is presently cultivated in a number of eastern countries. Shepherd's purse is one of the earliest wild greens in the spring. In the early spring, before the flowerstalks appear, the leaves are good in salads or cooked as greens. When the plant flowers, the larger basal leaves tend to die off, leaving only the smaller leaves clasping the stem. They're still edible, but they get tougher, develop more flavor, and become labor-intensive to collect.

-- Schusch 09:28, 12 September 2006 (UTC)

Sure, sounds great. But if I were including it, I'd want an original source to reference, not the commons. Aware of where this text was paraphrased from? Thanks! --Rkitko 15:24, 12 September 2006 (UTC)

colder climates

Kingdon, I concede "temperate" may be too narrow a description of its distribution, but how does "colder climates" help when you also point out that the distribution extends into subtropical areas? Anyway what does colder mean? Colder than what? Plantsurfer (talk) 19:23, 26 July 2008 (UTC)

The Flora of Pakistan source says "Distribution: Cosmopolitan in cooler climates mostly." Part of why I am reluctant to deviate from slight variants on this wording is that I don't really know enough about its distribution to know exactly what to say. You can see a US/Canada range map at PLANTS. Maybe something like "most climates" or "many climates" would be accurate. As the second-most common weed in the world (according to one of the sources, although I was reluctant to be quite that specific), the range seems to be pretty broad. Kingdon (talk) 20:00, 26 July 2008 (UTC)

The new atlas of the British flora defines its range as Circumpolar wide temperate(see article for reference).

Aksoy (see article for ref) states that Capsella bursa-pastoris occurs in cool temperate zones (oceanic\ suboceanic\ subcontinental and humid steppe climates) and in warm temperature subtropical zones (dry-summer Mediterrannean climates with humid winters and dry-summer steppe climates with humid winters)Plantsurfer (talk) 20:34, 26 July 2008 (UTC)

Wikiproject carnivorous plants

Excuse my regrettable ignorance, but why is Capsella bursa-pastoris within the scope of WikiProject Carnivorous plants? The connection would appear to be new to science.Plantsurfer (talk) 19:43, 26 July 2008 (UTC)

See references at Protocarnivorous plant. It would be nice to get at least a few sentences about that into this article. Kingdon (talk) 20:00, 26 July 2008 (UTC)

Thanks for that. Very interesting (especially if true, which personally I doubt).Plantsurfer (talk) 20:41, 26 July 2008 (UTC)

It's an interesting theory that I have not heard mentioned in ages. The seeds secrete or ooze a substance that is sticky and cotains protease. The substance traps nematodes and bacteria. The speculation was that that being a ruderal species C. bursa-pastoris somehow can use this ability to trap and digest organisms as a means of increasing nutrient uptake for seeds, making them better colonizers. This should be covered in more recent literature if it is the currently accepted theory. If so, it would be fun and interesting to include in the article.

Good job getting up a short little article, both of you. --Blechnic (talk) 07:52, 27 July 2008 (UTC)

Inasmuch as many (if not most) Brassicaceae seeds secrete a sticky substance when wet, it's probably not unique to Capsella.--Curtis Clark (talk) 14:11, 27 July 2008 (UTC)

Yes, garden cress Lepidium sativum (Brassicaceae) is a case in point. I'll never look at it in the same way again!Plantsurfer (talk) 14:36, 27 July 2008 (UTC)

Another "just so story" about the exudate is that it helps the seeds stick to the feet of birds for dispersal. Now that I know about the protease, I wonder if it isn't an antimicrobial, or perhaps a way of adjusting the microbiota away from species that would eat the embryo. There's a Master's thesis or PhD dissertation in that, if someone hasn't already done it.--Curtis Clark (talk) 15:41, 27 July 2008 (UTC)

Some references (just scratching the surface with Google):

• Differentiation of Mucilage Secretory Cells of the Arabidopsis Seed Coat pdf
• Mucilaginous seed coat structure ofCarrichtera annua and Anastatica hierochuntica from the Negev Desert highlands of Israel, and its adhesion to the soil crust
• Germinating seeds of Lesquerella perforata and stonensis : substrate effects and mucilage production (I worked on systematics of different Lesquerella species for my MS thesis.)
• Ecological Significance of Seed Mucilage in Desert Plants

Chia sages also have seed coat mucilage.--Curtis Clark (talk) 16:11, 27 July 2008 (UTC)

Very cool. I've only heard of it in relation to shepherd's purse. Makes me want to do a dissertation on the topic. The crucifers are biochemically fascinating plants. --Blechnic (talk) 19:06, 27 July 2008 (UTC)

The story about shepherd's purse and protocarnivory is commonly repeated enough that I think we probably need to say something about it. I've added something to the article, although I'm not sure anything which goes much beyond "the adaptive value of seed coat mucilage is unknown" is really justified by the evidence. Kingdon (talk) 16:16, 6 August 2008 (UTC)