Triosteum aurantiacum var. aurantiacum

Native

Dry. Woods, thickets.

May to June

Maroon, reddish-purple to brown, or yellowish-green

2′ to 4′

This is a 2′ to 4′ tall, erect, perennial forb rising on 1 or more stems from a taproot.

The stems are 2′ to 4′ tall and are covered with short, glandular hairs that are more than .5 mm long. Mixed in with the glandular hairs are longer non-glandular hairs.

The leaves are opposite, light green, untoothed, and attached to the stem without a stalk. They are 4″ to 12″ long, 1½ ″ to 6″ wide, and broadly-elliptic. They taper gradually to a pointed tip and taper broadly to the base. They have sparse, glandular hairs on the upper surface, and dense, soft hairs on the lower surface.

The inflorescence is a tight cluster of 1 to 4 (usually 3 to 4) flowers in the upper leaf axils.

At the base of the flower are 5 linear, erect sepals. They are uniformly hairy on the back and along the margins, and sometimes also have glandular hairs.

The flowers are ⅓″ to ⅔″ long with 5 maroon, reddish-purple to brown, or yellowish-green petals. The petals are fused into a tubular or bell-shaped floral tube along most of their length. The tube is swollen on one side at the base. The lobes of the tube are unequal in length. The style is shorter than and does not protrude from the floral tube.

The fruit is berry-like, dull orange-yellow, and hairy. Each fruit contains 3 oblong stones.

Late horse-gentian (Triosteum perfoliatum) stems are are covered with short hairs that are less than .5 mm long. At least 3 of the pairs of lower and middle leaves are fused at the base, appearing to be pierced by the stem. The style is longer than and protrudes from the floral tube.