The Fabaceae family has three subfamilies - Caesalpinioideae (senna genus), Faboideae (pea flowers) and Mimosoideae (acacia genus).
Looking at the acacia and peaflower flowers, one can't see the relationship - but the seedpods tell a different story.
There's 700 genera (18,000 species) in the Fabaceae family worldwide - with 180 genera (1,900 species) in Australia.
The Blue Mountains has over 270 species - including introduced species.
Sunshine Wattle (Acacia terminalis subsp. aurea)
There are an estimated 900 species of the Acacia genus in Australia. And this includes the Australian Floral Emblem, the Golden Wattle (Acacia pycnantha) - which is not indigenous to the Blue Mountains.
The greater Blue Mountains has over 100 Acacia species.
Although the Acacia genus is by far the largest genus in the Mimosoideae subfamily, PlantNET lists a further nine genera in NSW. Of these only the introduced Crested Wattle (Paraserianthes lophantha subsp. lophantha) is found in the Blue Mountains.
Pea Flowers(Faboideae subfamily)
Sandstone Parrot-pea (Dillwynia brunioides)
With over 1,100 species, the Pea Flower Faboideae subfamily is one of the largest in Australia. World wide there are some 12,000 species.
There are an estimated 160 species in the Blue Mountains including nearly 40 introduced species (weeds).
Pea flowers have five petals -
the standard or banner
two petals that are usually fused together and referred to as the keel.
Although flowering for all except the summer months, it's in winter when it's at its best - bringing brilliant splashes of yellow to the bush.
This is the main subspecies found in the upper Blue Mountains.
Here's another image.
The terete (long and cylindrical) sparsely hairy leaves with a mucro identifies this acacia, coupled with the white and red hairs on its peduncle (flower stalk).
It flowers in summer and autumn, and is found in swamps and next to watercourses in the Mid to Upper Blue Mountains.
By far the most prickly of similar species, this, and its brighter flowers and more pungent pointed leaves identify it.
Its phyllodes can be terete (cylindrical) or 4-angled as shown here.
It flowers from winter into spring.
This small prickly plant is identified by its very short peduncles (stalks). It is an uncommon species and is only found in the Upper and mid Blue Mountains.
Its flowers are 10mm across and phyllodes (leaves) up to 15mm in length.
another image and
This endangered species is recognised by its bright yellow globular flowers. Its bunched leaves are different to Acacia echinula, and its longer peduncles (stalks) distinguishes it from Acacia baueri.
It is mainly found in the lower Blue Mountains.
Here's another image.
The Cedar Wattle is a tall tree with dark brown rough bark.
The first set of its distinctive pinnate leaves are smaller than the rest.
It has a gland half way along its leaf stalk. This gland is known as a nectary and its nectar attracts pollinators.
This endangered plant mainly reproduces by suckers - which most probably helped its recovery from the Black Summer bushfires.
It received its common name, which means "bright star" in the Wiradjuri language, in 2020.
The broad standard identifies it as a Dillwynia species. Dillwynia elegans is identified by its terete (cylindrical), glabrous
(non-hairy) and warty leaves that have a point that is occasionally bent, and its glabrous calyx.
It was formerly called Dillwynia floribunda var. teretifolia.
Probably the most common Dillwynia, it is recognised by its twisted leaves Here's another image showing it being eaten by what looks like a weevil.
[There's an estimated 80,000 beetle species in Australia.]
Gompholobium genus - Golden Glory Peas
There's 11 species of Gompholobium in NSW - 10 of which can be found in the Blue Mountains.
Historically called Mirbelia grandiflora it also exhibits the heavily veined leaves of its sibling to the immediate left.
The flower is 10-12mm wide.
Here's another image.
[Note: The name "Large-flowered Mirbelia" is not commonly accepted.]
A small scraggy plant whose spring flowers are about 6mm across and have a red keel.
Its leaves are 10mm long, have a down-turned tip and are hairy underneath.
It is also known as the Small-leaved Bush-pea.
Only found in the upper Blue Mountains, it is identified by its hairy concave leaves and yellow keel. Its bracteole is reddish brown which helps distinguish it from P. tuberculata (which has a red keel).
There's 4 species of Phyllota in NSW - 3 of which can be found in the Blue Mountains.