Juncaceae: Rush Family

“Reeds and rushes are round, but sedges have edges.”  There is some truth in this popular saying, but it is not always correct.  Reeds and rushes vary from having cylindrical stems that follow with the pattern, to having grass-like leaves (oriented with their flat side towards the stem) or iris-like leaves (oriented with their edge towards the stem).  Some have stiff leaves, others have softer, floppier leaves.  A little attention to these details can help the identification process, since the difference between the flowers and fruits can be subtle.

Common Rush  – Juncus effusus subsp. pacificus

Blooms:

May–Oct

Plant Height:

< 115 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Seeps, shores, marshes, generally damp sunny ground

Notes:

The inflorescence appears to grow laterally from the stem about 20 cm from the top.  But, in fact, it grows at the tip of the stem; and what appears to be stem above the inflorescence is in fact a bract—with only a slight color-band marking to show where the stem ends and the bract begins.  The plant is densely tufted—a key diagnostic feature.  Only 3 rushes found in the county have inflorescences appearing to be lateral and grow in dense tufts.  Of these three, only two have green rather than blue-gray-green stems.  Of these two, only one has an open rather than a compact inflorescence.  Fruits are brown, oblong to truncate.  The lower stems have a dark sheath around their base.

Western Rush  – Juncus occidentalis

Blooms:

May–Sept

Plant Height:

30–60 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Moist areas

Notes:

This is one of only two rushes found in the county which have two bracts subtending the inflorescence (one is much longer than the other).  And this is the only one that ever has compact, clustered inflorescences.  Leaves are about ½ the length of the flowering stem, oriented like a grass, i.e. with the flat side towards the stem. The inflorescence is terminal, generally clustered near the coast, but more open when found inland.  Fruits are oblong to ovate, and 3-angled.

Spreading Rush  – Juncus patens

Blooms:

June–Oct

Plant Height:

30–105 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Moist areas in grassland and woods

Notes:

Like Common Rush (Juncus effusus, see above), the inflorescence appears to grow laterally from the stem about 20 cm from the top.  But, in fact, it grows at the tip of the stem; and what appears to be stem above the inflorescence is in fact a bract—with only a slight color-band marking to show where the stem ends and the bract begins.  The plant is densely tufted—a key diagnostic feature.  Only 3 rushes found in the county have inflorescences appearing to be lateral and grow in dense tufts.  Of these three, this is the only one to have blue-gray-green stems and 6 rather than 3 stamens on its flowers.

Brown-headed Rush  – Juncus phaeocephalus var. phaeocephalus

Blooms:

June–Aug

Plant Height:

10–50 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Shady or grassy places

Notes:

Like Iris-leaved Rush (Juncus xiphioides, see below), this small rush has leaves which are iris-like, oriented with the edge towards the stem.  The inflorescence appears terminal.  It is dark brown to dark purple or blackish in color, with anthers much longer than the filaments.  Fruits are narrowly ovoid.

Iris-leaved Rush  – Juncus xiphioides

Blooms:

July–Oct

Plant Height:

40–80 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Wet places

Notes:

The common name points to one of the distinguishing feature of this rush.  Namely, its leaves which are iris-like, oriented with the edge towards the stem, 5–14 mm wide, unlike most rushes in the county.  The inflorescence is green or reddish, comprising a number  of fairly open clusters.  The anthers are pink, more or less the same length as the strongly exserted filaments.  Fruits are oblong, abruptly tapered towards the beak.

Sessile Wood Rush – Luzula subsessilis

Blooms:

Apr–July

Plant Height:

20–30 cm

Flower Size:

Small cluster

Origin:

Native

Habitat:

Open, dryish woodland

Notes:

Although the flowers resemble those of Brown-headed Rush (Juncus phaeocephalus, see above), this is a much smaller plant.  Also, it has very different leaves, thin, soft and grass-like, unlike the stiffer leaves found in the Juncus species.  The leaves are slightly hairy on the margins.  This species comes in two forms, one with 1 or 2 dense heads and the other, more widespread, with a branched umbel-like inflorescence.  There is a single bract subtending the inflorescence, 1.5–7 cm long, generally shorter than the inflorescence.