From the BD of Hanoi, the rendezvous point of each botanical exploration, we descend through the staircase of the trail of the Teucrium pseudochamaepitys, and notice a very early flowering of the famous plant protected nationally, next to a Euphorbia ” morning alarm clock “(Euphorbia helioscopia). This will be the theme of a future exploration because on that day, we were more particularly interested in euphorbic.
For the second botanical exploration of the year on 2 March, it was very beautiful, we went to herborize in a place where nobody goes, hardly accessible, below the big letters and above the Timonnerie.
The descent of the slopes, between the euphorbs. It’s gone for the identification of plants here present… not easy!
The euphorbic (EuphorbiaL.), feminine name, possess special inflorescences named cyathes, peculiarity that they share only with some neighboring genera. These are poisonous plants, which possess a white LaTeX sometimes very irritating.
In temperate species, the appearance of flowering plants varies greatly over the course of days: leaves tend to disappear as the umbelle develops, the stem blushes, while the fruit, a three-celled gloomous capsule, emerges very quickly from the inflorescence.
The word Euphorbia would come from euphorbium, the name given by King Juba of Mauretania, in honor of his Greek doctor Euphorbus, to the medicinal drug made from the LaTeX of the species today named Euphorbia resinifera.
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The euphorbs are generally recognized with their yellowish-green inflorescences, or cyathes, arranged in ombelles, having neither sepals nor petals. Each inflorescence contains a three-style female flower surrounded by male flowers, all in a cut formed by two bracts bearing four or five often-corbare glands. The fruit, pedicellated, is a capsule usually very rounded, smooth or grainy.
We searched the floras (books) to determine the exact name of the most present Euphorbia in this place. It is called Euphorbia graminifolia, a fine-leaved Spurge, with a red stem at flowering and almost more leaves. The most common in the gardens is also there, Euphorbia helioscopia or euphoria awakening-morning.
The Euphorbia is part of the same family as the rubberized rubber latex, which grows mainly in the Amazon.
In 1935 in Minnesota, Carl Pfaender a farm worker is enthusiastic about the laticiferous potential of spurge esula, which produces a rubber of as good quality as those imported. Euphorbia is, at that time, considered in the United States as a poisonous and invasive plant to eradicate. Carl Pfaender is still in the manufacture of rubber. In 1941, under pressure from his neighbours, he was obliged to pay pesticides himself on several hectares of plants which he took care of as a future LaTeX crop. This is the end of his Euphorbia rubber adventure.
In 1942, in order to contribute to the war effort, botanists explored the possibility of producing rubber on American soil. Ross A Gorter, head of the biochemistry Division at the University of Minnesota, suggests that weed becomes a permanent crop in marginal and regeneration lands in Northern Minnesota and North Dakota. Scientists predict a yield of 170 to 220 kilos of rubber per hectare, which is considered a good yield.
Three days later, the Minneapolis morning Tribune mixes the data and announces a figure of 150 to 198 “tons”, instead of kilo per hectare. Hundreds of farmers are offering their land to work and transform the Euphorbia. When we discover the modest reality of performance, this whole affair is immediately an insurmountable embarrassment and signs the end of the rush to the rubber Euphorbia.
Extract of guayule and other rubber plants from yesterday’s saga to the industry of tomorrow, by Mark R. Finlay
There was also the mauve, which is no longer present, the leek of the vines…
Plants identified on the parcel:
Allium ampeloprasum the wild leeks, Euphorbia graminifolia (tenuifolia), Euphorbia helioscopia euphoria alarm clock, malva sylvestris la mauve, mercurialis Annua la mercuriale, betta maritima la chard Sauvage, pipterium milliaceum a great grass, Phragmites australis common Reed, verbasmula sinuatum sinuous-leaved mullein, Scabiosa la scabieuse, Diplotaxis erucoides white rocket, sonchus oleraceus Le perennial sow thistle market
The botanical explorations are walks that invite to make together the inventory of the flora of ForestA, and make this data accessible to all on the site TELA Botanica. To participate in other botanical explorations it is here
Photos of Shéryl Debourg (Yes we camp) and Isabelle Dor