YELLOW-RATTLE

HAY-RATTLE

Rhinanthus minor

Broomrape Family [Orobanchaceae]  
Formerly in: Figwort & Foxglove Family [Scrophulariaceae]

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status
statusZnative
flower
flower8yellow
inner
inner8orange
morph
morph8zygo
petals
petalsZ2
stem
stem8round

9th June 2008, Humphrey Gate, Taddington, White Peaks. Photo: © RWD
A limestone-area pasture-field full of Yellow-Rattle.


9th June 2008, Humphrey Gate, Taddington, White Peaks. Photo: © RWD
Encouraging the growth of Yellow-Rattle in a meadow greatly increases biodiversity because the plant is  Hemi-parasitic on grasses and restricts their growth. Some meadows are especially sown with Yellow-Rattle seed for this very purpose.


9th June 2008, Humphrey Gate, Taddington, White Peaks. Photo: © RWD
Ribwort Plantain is the tall plant surrounding Yellow-Rattle, which grows up to 50cm tall.


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
Yellow flowers peep out of a green calyx pod like a cuckoo (or canary, since it is yellow) out of a cuckoo clock.


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
Leaves are oblong to linear, in quadrature pairs opposite each other and attached directly to the single stem without stalks. They have convexly-rounded forwardly-directed bluntish teeth not dis-similar to those of Betony. The topmost leaves look as though they are perfoliate, with the leaf wrapped all around the stem which penetrates the leaf.

Branches may appear in pairs from just above lower leaf-pairs.



9th June 2008, Humphrey Gate, Taddington, White Peaks. Photo: © RWD
The four pale-green sepals are fused to form an enclosure with just a small opening to accommodate the narrow throat of the flower. The opening has four blunt triangles. Flower is yellow to brownish-yellow with bi-lateral symmetry. The upper lip of the flower is curved, the lower lip drooping slightly. Tellingly, the corolla tube is straight (flower lower right) [and not curving upwards] which indicates it is not Greater Yellow-rattle.


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
Some books state that in Greater Yellow-rattle the stigma visibly protrudes a short distance, whereas it does not protrude in Yellow-rattle, but the length or visibility of the stigma (or not) does not feature in Clive Stace's ID key for Yellow-rattles. In the above photo the stigmas are visible (and seem to be protruding) in the lower right flower and top flower. (So this non-deterministic feature may well by the reason why Greater Yellow-rattle is over-reported, which it is according to Stace).


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
If the two teeth are wider than they are long, then it is Yellow-rattle. (But if longer than wide, then it is Greater Yellow-rattle). In this specimen, the side-lobes of the three-lobed lower lip (of which only one lobe is clearly visible) seem to be like roundish paddles or dolphins flippers.


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
Some sub-species have short hairs on the calyx (sepals), and on the flowers too. Flower cradled on top of a leaf.


31st May 2008, Middlesclough, Broughton In Furness, Cumbria. Photo: © RWD
Some teeth are white instead of purple.


23rd May 2008, Shell Island, North Wales. Photo: © RWD
The upper lip has a short purple-coloured (or white) tooth slightly protruding. The lower lip has two cuts giving it three lobes, but which often are not clearly visible.


30th May 2014, arable fields, Downham, Lancs. Photo: © RWD


9th June 2008, Humphrey Gate, Taddington, White Peaks. Photo: © RWD
From the front, the lower can be more-clearly seen to have three lobes. The two teeth each on side are seen to be narrow on a full frontal view.


2nd July 2015, Ainsdale Dunes, Sefton Coast. Photo: © RWD
The stamens (brown) and style (green, top) are deep within the beak of the 'canary'.


8th July 2014, dune slacks, Ainsdale, Sefton Coast, Ainsdale Photo: © RWD
The seed pods (calyx) are maximally inflated when the seeds are ripe.


8th July 2014, dune slacks, Ainsdale, Sefton Coast, Ainsdale Photo: © RWD
The calyx, when the seeds are rip, turns purple-brown and is cupped by a short, coarsely-toothed, leaf/bract(?) on short stalks.


2nd July 2015, Ainsdale Dunes, Sefton Coast. Photo: © RWD
The two sepals of the calyx peel back to reveal a nearly round seed-pod with a short point at the tip.


2nd July 2015, Ainsdale Dunews, Sefton Coast. Photo: © RWD
Within the seed pod are over numerous discoidal seeds usually possessing a marginal flange (wing), three of which your Author has squeezed out after breaking the seed-pod. Your Author supposes that it is the seeds within the seed-pod (and not the seed-pod within the calyx) which rattle when ripe and shaken. This calyx contained 2 seed-pods, your Author does not know if that is typical, or not.


30th May 2014, arable fields, Downham, Lancs. Photo: © RWD
Some specimens have two side-branches which emerge just above a pair of leaves.


30th May 2014, arable fields, Downham, Lancs. Photo: © RWD
The stems are flecked with purplish-brown streaks.


Some similarities to : There are reportedly six sub-species of Yellow-Rattle, differentiating between them is best left to experts with more patience but it will likely just drive them round the bend.

Slight resemblance to : A canary clambering out of an eggshell, with its' mouth agape. Many similarities to Greater Yellow-rattle (Rhinanthus angustifolius) but that has longer teeth (1-2mm rather than just 1mm for Yellow Rattle) on each side of the upper lip and they are longer than wide (as opposed to wider than long for Yellow Rattle). Also, the corolla tube curves upward (rather than being straight in Yellow Rattle), although the Author thinks you may have to dismantle the flower to see wether the corolla tube is straight or curves upwards for much of it will be hidden within the four coarsely-toothed fused sepals, being the calyx.

Uniquely identifiable characteristics: Apart from much rarer (RRR) Greater Yellow-Rattle, which looks very similar, there are no other plants that have the same jizz as Yellow-Rattle. If the two teeth on either side of the upper lip are wider than they are long, then it is Yellow-rattle; if longer than wide, then it is Greater Yellow-rattle).

Distinguishing Feature : looks like a canary emerging from its' eggshell with mouth agape.

This is a  Hemi-parasitic plant, meaning that it relies on obtaining some of its' nutrients from the roots of nearby plants. The flowers themselves have a beaked appearance that resembles those of Red Bartsia which is another hemi-parasite but the flowers of Yellow-Rattle are larger.

One of the effects of its parasitic nature is that it reduces the abundance of grasses by suppressing their growth.

Yellow-Rattle derives its' name from the loose seeds within which rattle around in their pods when ripe. The scientific name 'Rhinanthus' is a flower that looks similar to a nose, which probably refers only to the seed pods. It is highly variable in several characteristics and displays ecotypic variation; that is variation due to the ecology of its immediate surroundings.

There are six reported sub-species of Yellow-Rattle, those shown in the above photographs could be any number of them, most are either rare [RR], or very rare [RRR].

  • Rhinanthus minor ssp. lintonii [RRR]
  • Rhinanthus minor ssp. borealis [RRR]
  • Rhinanthus minor ssp. calcareus [RRR]
  • Rhinanthus minor ssp. minor
  • Rhinanthus minor ssp. monticola [RR]
  • Rhinanthus minor ssp. stenopyllus [R]
Rather than list the proclaimed differentiations between these six, the Author shall just instead report that Clive Stace says that some populations of Rhinanthus major do not fit any sub-species descriptions, with the situation on the continent being even more complex, and that perhaps the sub-species might be best abandoned. If the reader is dissatisfied with this, then the Author herewith lists a few of the reported discriminations between the six:
  • Calyx hairy all over or only on margins.
  • Branches in 0-2 pairs, or not, or in 0-1 pairs.
  • Leaves linear-lanceolate or linear-oblong
  • Lowest flower at node 7-10 or at node 5-7 or 8.
  • Stems less than 25cm or less that 50cm long
  • Leaves mostly tapering near the base or leaves mostly parallel-sided
  • Leaves mostly in 0 to 1 pairs or leaves in 0 to 4 pairs.
  • Lowest flower usually between 7th - 13th node or between 6th - 9th node.
  • Corolla usually yellow or usually dull brownish-yellow
These characteristics are not mutually exclusive, but used in various combinations for the six sub-species.


  Rhinanthus minor  ⇐ Global Aspect ⇒ Orobanchaceae  

Distribution
family8Broomrape  family8Orobanchaceae

 BSBI maps
genus8Rhinanthus
Rhinanthus
(Yellow-rattles)

YELLOW-RATTLE

HAY-RATTLE

Rhinanthus minor

Broomrape Family [Orobanchaceae]  
Formerly in: Figwort & Foxglove Family [Scrophulariaceae]

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