Galium borealis L.

Galium borealis plant

Family - Rubiaceae

Stems - Multiple from the base, branching, herbaceous, 4-angled, to +/-40cm long, ascending to erect or reclining, glabrous to sparse retrorse strigose, with bumps and the angles, from a small crown and fibrous roots.

Galium borealis node

Leaves - Whorled, 4 at a node, sessile, linear-lanceolate, to +/-4cm long, +5mm broad, with three main nerves, entire, with ciliate margins, glabrous above, sparsely pubescent below, green above, light green below. Veins of leaf impressed above, expressed below.

Galium borealis leaves

Inflorescence - Terminal cymes to +10cm long and broad. Each division of the cyme subtended by a pair of elliptic bracts. Bracts reduced upward, with retrorse hairs at the base. Pedicels and peduncles of cyme glabrous, 4-angled, often with hairs in their axils. Pedicels to 4mm long.

Galium borealis inflorescence

Flowers - Corolla white, 4-lobed, +/-3mm broad. Corolla tube conic, -1mm long. Lobes acute, glabrous, +1mm long and broad, ovate-oblong, entire. Stamens 4, alternating with the corolla lobes, adnate at the apex of the corolla tube, erect, exserted. Filaments to .7mm long, white, glabrous. Anthers yellow-brown, .2-.3mm long. Style 1, glabrous, white, slightly exserted, bifurcate in the apical 1/2, +1mm long. Stigmas capitate, translucent, .1-.2mm broad. Ovary inferior, light green, with antrorse hairs, bilobed, .7mm long in flower, .8mm broad.

Galium borealis flower

Galium borealis fruitFruit.

Flowering - May - July.

Habitat - North-facing ledges and crevices of limestone bluffs.

Origin - Native to U.S.

Other info. - This species is extremely rare in Missouri and can only be found in two counties in the state. The plant is a relic from before the retreat of the Pleistocene ice sheets. It has remained only in the cool, north-facing bluffs along the Jack's Fork River.
In Missouri G. borealis doesn't take the erect form that it is capable of. Plants in this state hang from the rock crevices from which they grow and look like this:

Galium borealis plant

Photographs taken along the Jack's Fork River, Shannon County, MO., 6-22-03.


Back