Can anyone give me some clues as to the species, please? Plant is about 1m tall. Flowers are very small (under 1 cm), yellowish & short lived (I couldn't find any open to photograph). Growing in moist ditch in the Fraser Valley BC.
Yes, now you point it out, I can see it. These plants are overheight for the descriptions & the flowers smaller to the point of being almost inconspicouous. I have not seen it in the Fraser Valley before. Thanks - again.
Your population may have cleistogamous (much reduced) flowers. http://www.geobot.umnw.ethz.ch/teaching/V_Unterlagen/HTML/RP_FS09/Hatcher2003.pdf
That's it. I took another look today & the small (30-50mm) flowers wither without opening & the immature pod is right there. Cleistogamy is more prevalent in this species in Europe in shaded areas it seems, according to the paper you referred me to. These plants are duly growing in a shady area. ...this forum is amazing. Good one, saltcedar.