Juncus heldreichianus is a large tufted species of rush in the family Juncaceae, formed of two subspecies.
A large, densely-stemmed rush, forming individualised (poorly-creeping) plants; subsp. heldreichianus attains 100–150 cm with rather arching stems, subsp. orientalis reaches 70 cm.
Inflorescences for subsp. heldreichianus are usually long and narrow, appearing stretched-out, with well-spaced lax floral heads (therefore resembling J. maritimus, which however usually forms creeping patches), whilst for subsp. orientalis the inflorescence is composed of a closer spray of well-separated heads of flowers.
The individual flowers have 6 tepals typical of the genus Juncus, but with the inner 3 with broad pale margins, notched at the top, the flowers having an over all light brown colour (J. littoralis being dark brown).
The mature fruit capsules are up to 4 mm (J. acutus 4–6 mm) with blunt seams converging as a blunt tip (J. littoralis having sharp seams converging to a sharp pyramidal tip).
Seeds are small (0.8-0.9 mm long, 1.0-1.5 mm with appendages) compared to J. littoralis (0.8-1.1 mm long, 1.5-2.0 with appendages).[1] [2]
Species - Albania, Cyprus, East Aegean Is., Greece, Iran, Kriti, Lebanon-Syria, Tadzhikistan, Transcaucasus, Turkey, Turkey-in-Europe, Turkmenistan.[3]
Juncus heldreichianus subsp. heldreichianus - Albania, Cyprus, East Aegean Is., Greece, Kriti, Turkey, Turkey-in-Europe.[4]
Juncus heldreichianus subsp. orientalis - Iran, Lebanon-Syria, Tadzhikistan, Transcaucasus, Turkey, Turkmenistan.[5]
Juncus heldreichianus subsp. heldreichianus - Sand dunes, sandy places, salt and freshwater marshes, along streams, from sea level to 1700 m.[1]
Juncus heldreichianus subsp. orientalis - Permanently or seasonally wet places, slightly to strongly saline habitats, known from sites between 800 and 1700 m.[1]