Lace Lichen

Lace Lichen (Ramalina menziesii) is a pendent fruticose lichen in the family Ramalinaceae, and one of the most photogenic lichens in North America. Its thallus develops into a reticulate mesh — a genuine net of interconnected flattened strands with open windows between them — that drapes from branches in curtains that can exceed a metre in length.

Most Ramalina species produce simple flattened straps; R. menziesii is unusual in the genus for elaborating those straps into a lattice, apparently an adaptation for intercepting fog droplets over the largest possible surface area for the least tissue.

The species is strongly associated with the Pacific coastal fog belt and was designated the state lichen of California, where it festoons valley oaks, coast live oaks and other trees in a way that is often mistaken at a distance for Spanish moss.

Thallus form

The thallus is pendent and fruticose, hanging in strands 10 cm to over 100 cm long from a small holdfast on a branch. The defining feature is the net: strands repeatedly fuse and rejoin to enclose regular open meshes, producing a lace or fishnet texture. Narrow, unbranched, non-netted forms occur in drier inland sites and are harder to recognise.

Colour and surface

Colour is pale greenish-grey, whitish-green or straw-green, similar on both faces — there is no dark or white underside. The surface is smooth to slightly wrinkled, and the strands are flattened, thin and pliable when moist, becoming papery and brittle when dry.

Fruiting bodies

Apothecia are pale, concave to flat, disc-shaped and borne on the margins and tips of the netted strands. They are pale buff to greenish rather than dark, blending with the thallus.

Texture check

Breaking a strand shows a thin cortex around a loose white medulla, with no elastic central cord — a quick way to separate it from beard lichens.

Lace Lichen grows on the bark and branches of trees and large shrubs, with oaks — valley oak, coast live oak, blue oak — as classic hosts, along with willows, alders, bays, pines, cypress and even fenceposts and utility structures. It reaches its greatest development in the fog belt, in open oak savanna, riparian corridors and coastal woodland where frequent summer fog compensates for the dry season.

Its range runs along the Pacific coast from Alaska and British Columbia south through Washington, Oregon and California into Baja California, with related populations reported further south. It is perennial and present in all seasons, appearing limp and green after fog or rain and pale, dry and crisp during hot spells.

Ramalina menziesii is an epiphyte that takes no nourishment from its host tree, using branches only as an anchor. Its open mesh is highly effective at combing water droplets out of drifting fog, and heavily lichened trees measurably increase fog drip to the ground beneath them, redistributing moisture in an otherwise summer-dry landscape.

The lichen contributes to nutrient cycling as fragments fall and decay, and the curtains are heavily used by wildlife — birds strip strands for nest material and the hanging mats shelter large numbers of invertebrates. Dispersal is chiefly by fragments broken off in wind, augmented by spores from the pale marginal apothecia.

Usnea species hanging from the same oaks are separated instantly by the tough white elastic central cord inside every branch: gently pull a strand and Usnea stretches then snaps to reveal the cord, while Ramalina breaks cleanly with no cord. Usnea branches are also round in cross-section rather than flattened.

Ramalina leptocarpha and other local Ramalina species share the colour and flattened straps but never develop the interconnected net, remaining simply branched. Alectoria sarmentosa is a hanging pale yellow-green species with round, smooth, freely branching filaments that never fuse into a lattice. True Spanish moss (Tillandsia usneoides) is a flowering plant, with grey scaly wiry stems and slender leaves rather than a flattened lichen thallus.