Greenbriers & Yams

Glaucous Greenbrier Round-leaved Greenbrier Wild Yam Glaucous Greenbrier

What are they?

Greenbriers are the bane of anyone who has tried to strike out into New Jersey woodland, away from the main paths. The main stems are well armed with strong thorns which can tear clothing as well as skin and the stems of some species can straggle way up into the tree canopy. Wild Yam is included here as its trailing stems resemble a weak greenbrier, but it is thornless.

Where are they found?

Greenbriers are abundant in woodland and other shady habitats, particularly in damp ground. Some species are more common in drier, sandy soils around the coast.


Some species are woody, while others are herbaceous, that is to say, they die down during the winter and sprout from the base again the following spring. This fact, coupled with leaf shape should identify the species, while berry color is useful also.

Smooth Carrion-flower      Smilax herbacea

Widespread in shady, usually damp, woodland. Flowers May to June. Leaves thin and pliant, not thick and waxy like other greenbriers.
Smooth Carrion-flower Smooth Carrion-flower Smooth Carrion-flower Smooth Carrion-flower
Male flowers
Female flowers
Leaf underside smooth

Coastal Greenbrier      Smilax pseudochina

An uncommon plant that may be found in woodland edge habitats in a variety of soils. Flowers June to July. Stems spineless and herbaceous, not becoming woody. Leaves have a slightly rough feel and are usually concave at the sides, sometimes forming two lobes at the leaf base.
Coastal Greenbrier Coastal Greenbrier Coastal Greenbrier
Typical leaf
Flower buds
Male flowers

Glaucous Greenbrier      Smilax glauca

(Cat Greenbrier) Common and often dominant in dry, sandy fields and coastal dunes. Often trails over the ground. Flowers May to July.
Glaucous Greenbrier Glaucous Greenbrier Glaucous Greenbrier Glaucous Greenbrier
Leaves blue-green,
especially underneath
Stems with same glaucous
bloom as leaves
Berries with strong
glaucous bloom

Round-leaved Greenbrier      Smilax rotundifolia

A very common component of almost all woodland in the county, wet and dry. Flowers May to June. An abundant plant, its spiny, clambering stems all too easily found by those venturing off the trail!
Round-leaved Greenbrier Round-leaved Greenbrier Round-leaved Greenbrier
Leafy shoot

Round-leaved Greenbrier Round-leaved Greenbrier
Stems bright green
Berries with strong
glaucous bloom

Laurel-leaved Greenbrier      Smilax laurifolia

A rare plant of wet, undisturbed woodland. Flowers August to September. A straggling plant which shares the general appearance of other greenbriers but with much narrower leaves. Flowers later than other species.
Laurel-leaved Greenbrier Laurel-leaved Greenbrier Laurel-leaved Greenbrier
Typical young plant
Leaves on older plant

Laurel-leaved Greenbrier Laurel-leaved Greenbrier
Stout spines on older stems

Walter's Greenbrier      Smilax walteri

(Red-berried or Coral Greenbrier) An uncommon scrambling plant of wet woodland which may occasionally be locally common in the north of the county. Flowers May to June. Best told by its red berries; leaves variously shaped but generally narrower and less rounded than those of Round-leaved Greenbrier.
Walter's Greenbrier Walter's Greenbrier Walter's Greenbrier
Leafy shoot

Walter's Greenbrier Walter's Greenbrier Walter's Greenbrier
Main stems have few thorns
Upper stems thornless
Berries red

Wild Yam      Dioscorea villosa

Found in loamy woodland soils; not infrequent but easily overlooked as plants are often rather small and thin-stemmed. Flowers June to July.
Wild Yam Wild Yam Wild Yam Wild Yam
Flower spike
Heart-shaped leaves
with distinct veins
Young leaves bright green

Wild Yam
Seed pods