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DYER'S GREENWEED

DYER'S BROOM

Genista tinctoria

Pea Family [Fabaceae]

month8jun month8june month8jul month8july month8aug

category
category8Shrubs
category
category8Broadleaf
category
category8Deciduous
status
statusZnative
flower
flower8yellow
morph
morph8zygo
petals
petalsZ5
type
typeZspiked
stem
stem8round
stem
stem8ribbed
toxicity
toxicityZmedium

Genista tinctoria ssp. tinctoria

Dyer's Greenweed exists as two sub-species, ssp. tinctoria and ssp. littoralis, with the former not being rare, but the latter is so rare as to deserve a Stace rating of [RRR]

1st July 2009, Newtown NNR, Isle of Wight Photo: (CC by 2.0) Mike Cotterill
Not un-like a very short Spanish Broom.


1st July 2009, Newtown NNR, Isle of Wight Photo: (CC by 2.0) Mike Cotterill
Grows to 60cm, usually upright.


1st July 2009, Newtown, Isle of Wight Photo: (CC by 2.0) Mike Cotterill
Has a spike of yellow flowers nearer the summit.


1st July 2009, Newtown, Isle of Wight Photo: (CC by 2.0) Mike Cotterill
The stems are almost straight (like those of Spanish Broom) but it has short narrow elliptical and hairless simple leaves almost all the way up the stem (not just only near the bottom like Spanish Broom - which is in a differing genus, Spartium).


1st July 2009, Newtown, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Flowers all-yellow.


13th June 2009, a copse, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Flowering stalks branch off from the main stem at ~60° angle to it.


13th June 2009, a copse, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Flowers with long narrow banners, two curved and cupped wings with the cupped keel usually between the wings. Larger flowers than any other Genista species: 10 to 15mm. The plant is never spiny, so cannot be mistaken for any Gorse plant (which is in the same genus, Genista). The jizz of the flowers is of one with a very long narrow face.


13th June 2009, a copse, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Calyx, corolla and leaves usually hairless.


13th June 2009, a copse, Isle of Wight Photo: (CC by 2.0) Geoff Toone
But as you can see, the leaves and stems might have a few short hairs, or might not. Leaves simple, elliptical, narrow and short. Leaves have very short stalks and are nearly sessile.


12th Aug 2017, a meadow, Newton, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Fruits 15-30mm long, nominally hairless, but as you can se there are hairs on these specimens. Leaves usually hairless and >4 times longer than wide (if < 4 times longer than wide and hairy then the plant is probably the rare [RRR] ssp. littoralis)


12th Aug 2017, a meadow, Newton, Isle of Wight Photo: (CC by 2.0) Geoff Toone
Fruits (pods).


Dodder on Dyer's Greenweed

Porchfield, Isle of Wight Photo: (CC by 2.0) Richard Smout
Dodder behaving parasitically on Dyer's Greenweed.



Genista tinctoria ssp. littoralis

This sub-species is so rare as to deserve a Stace rating of [RRR]. So rare, in fact, that your Author has not got a photograph of ssp. littoralis


Easily confused with : Flower () [a plant of similar name]

Not to be mistakenly identified for : Spanish Broom (Spartium junceum) [a plant with similar name and similar yellow flowers in the same Pea family but in a differing Genus]

Easily mistaken for : Flower ()

Easily mis-identified as : Flower ()

Genista tinctoria occurs as either of two sub-species :

  • Dyer's Greenweed (Genista tinctoria ssp. tinctoria) which is not rare and has leaves > 4x longer than the width and with fruits that are hairless. Grows in grassy places and rough ground being only locally common in Britain north to Southern Scotland, and in Jersey and IoW.
  • Dyer's Greenweed (Genista tinctoria ssp. littoralis) which is a very rare [RRR] which is procumbent and with leaves <4x longer than the width and with fruits that are either hairy or hairless. It grows on Cornish, North Devon and Pembrokeshire cliffs, so you wont find your Author looking for it.

Many similarities to : Hairy Greenweed (Genista pilosa) which is a very rare [RRR] and in the same Genista genus, but which has hairy flowers (on the banners and keels) with slightly shorter hairy fruits (pods).

Slight resemblance to : Flower ()

Superficial resemblance to : Flower ()

Lookee-Likees : Flower ()

Uniquely identifiable characteristics

Distinguishing Feature :

No relation to : Green Alkanet (Pentaglottis sempervirens), [a plant with similar name along with dozens of other plants beginning with 'green'].

FLAVONOID & ISOFLAVONOID DYES

Dyer's Greenweed, aka Dyer's Broom, was once used as a yellow dye. The dye produced contains a mixture of yellow compounds called flavones and isoflavones, the proportions and amounts of which vary from year to year, season to season and location to location. The major dye constituents are the flavonoids Chrysoeriol and Diosmetin plus the IsoFlavonoids Genisteine, Daidzein and its glycoside Daidzin.


FLAVONOIDs

There are two main flavonoids found within Dyer's Greenweed, Chrysoeriol and Diosmetin, the latter of which differs only by a missing -OH group. Chrysoeriol is also found in plants of genus Artemisia, such as Mugwort and Wormwood. Chrysoeriol and Diosmetin (aka Luteolin 4'MethylEther) are positional isomers (aka regioisomers) of each other. Diosmetin is the aglycone (without sugar moiety) of Diosmin (which should not be semantically confused with Geosmin). The non-native Caucasian Vetch also contains Diosmetin. IsoFlavones are also exhibit anthelmintic and antioxidants properties in the mammalian body.


ISOFLAVONOIDs

There are two main isoflavonoids found within Dyer's Greenweed, Genisteine (from which the flavonoid is named) and Daidzein, the latter of which also differs only by a missing -OH group, but one which is in a differing position to that of the flavonoids.

Genisteine is also found in Lupins, Soybeans, Fava Beans and several other members of the Pea (Fabaceae) family. Genisteine is a phytoaestrogen which are plant-derived substances which also exhibit an aestrogenic effect within the mammalian body but are not produced by mammals. Consumed phytoaestrogens seem to have a protective effect against a diverse range of conditions such as prostrate cancer, breast cancer, bowel cancer, osteoporosis, brain function disorders and cardiovascular diseases amongst other. IsoFlavones are normally found in plants in the glycosolated form.

Daidzein is only found in species of plants belonging to the Pea (Fabaceae) family and has similar effects on the mammalian body, described above, as does Genisteine.



AN ISOFLAVONOID GLYCOSIDE

Daidzin is a glycoside of the above isoflavonoid Daidzein. Based upon animal studies Daidzin seems to promise a treatment for alcohol dependency.


Other studies report that the main dye components are Luteolin, Apigenin and Genisteine with Chrysoeriol and Diosmetin as more minor constituents in the dyes analysed after the wool has been dyed with Dyer's Greenweed. But obviously, the process of dying the wool might well change the proportions of Flavonoids and IsoFlavonoids found in the wool after dying, especially if the examined dyed wool is very old, as it was. These are totally different measurements from assaying the plant composition directly.


  Genista tinctoria  ⇐ Global Aspect ⇒ Fabaceae  

Distribution
 family8Pea family8Fabaceae

 BSBI maps
genus8Genista
Genista
(Greenweeds)

DYER'S GREENWEED

DYER'S BROOM

Genista tinctoria

Pea Family [Fabaceae]