#polygonaceae

Eriogonum grande var. rubescens

California has a large number of wild buckwheat species, belonging to the genus Eriogonum and placed in the family Polygonaceae. Most of these have white, pink or yellow flowers, but Eriogonum grande rubescens is redder than the others, making a wonderful show of many rounded heads of tiny flowers that contrast beautifully with the silvery or green color of the leaves. Eriogonum grande is closely related to E. latifolium, and considerd by some authors to be a form of that species. Native to southern California's Channel Islands.

Bistorta plumosa (Polygonaceae)

meadow bistort

You know what? It's been a while since I posted a vascular plant and these were one of my favourites from the bioblitz.

Pileurtbladbille (Gastrophysa polygoni)

På kruset skræppe (Rumex crispus).

Gastrophysa polygoni (Gastrophysa polygoni)

Another one from Lake Richmond, where it was growing around the end of the thrombolite-viewing boardwalk. I took some to the AgDept along with some of the other weeds, since the herbarium didn’t have any Persicaria from that locality, but their closer look turned up a bit of a surprise. 

“The Persicaria from Lake Richmond has Ocreas (stem bracts) that have  ciliate  margins (P. hydropiper character), Leaves also have ciliate margins. Flowers are white/green, in distinct clusters not dense and overlapping as in normal P. lapathifolia BUT leaves have scattered yellow glands underneath (not dense) and this is a defining character of P. lapathifolia. I wonder if this is a form of lapathifolia or a hybrid with P. hydropiper (within this species range), it could have come from a garden or who knows where.”

If it is a hybrid, lets hope it doesn’t have the kind of hybrid vigour that turns it into a major weed. 

Persicaria is a cosmopolitan genus in the Polygonaceae, known as knotweeds and smartweeds. It includes annual and perennial herbs with taproots, fibrous root systems, rhizomes or stolons. The stems are often erect but may be prostrate along the ground, and some species protect themselves with prickles. The stems can be strong enough to support themselves, twining and climbing.b The flowers might be white, greenish, reddish, pink or purple, groewing in an inflorescence as here.  The fruit are seed-like achenes - where the fruit wall (pericarp) encloses the solitary seed so closely as to seem like a seed coat - and might take a number of shapes, including a disc or a sphere (the ‘seeds’ on the outside of a strawberry are also achenes).

As for the two species implicated above, lapathifolia is also known as pale persicaria, and a weed in Britain and Europe. Other common names for the plant include pale smartweed, curlytop knotweed, and willow weed. It grows near water and in disturbed ground, rubbish tips and verges in many parts of the world, and the form of the plant varies widely depending on local conditions.