Yellow Puff (Wildlife and Wildflowers of Texas - Wildflowers Pt. 1)

Yellow Puff

Neptunia lutea

Other Names ⁶

Yellow Sensitive-Briar, Yellow Neptunia

Blooming Season ⁶

May-June

Identification ⁶

(1) Neptunia lutea is a trailing, vine-like perennial. Its stems are covered with soft spines, but is not nearly as prickly as the similar-looking Mimosa nuttallii. The sprawling stems of this plant branch frequently, with each branch growing as long as 5 ft. Leaves are alternate and stalked, bipinnate, looking much like tiny fern fronds. The flowers are tiny and arranged in a slightly elongated, congested bundle (inflorescence) containing 30-60 flowers each. The unopened bud clusters look much like green bramble fruits. Each individual flower has five minute petals and ten stamens. When the flowers open, the inflorescence looks like a puffy yellow ball, with usually only the long yellow stamens visible. The inflorescence rests solitary at the end of a slender stalk. Like some Mimosa, the leaves of this plant exhibit rapid plant movement. They will close upon touch, as well as at night and during periods of cloudy weather.
(2) Neptunia can be distinguished from other similar bipinnately compound legumes by the presence of a stipe on the legume. N. lutea can be distinguished by having 8-18 pairs of leaflets and 30-60 flowers per head, a 4-15 mm long stipe and 1-2 mm long calyx (including lobes).
(3) It is a perennial with a thick taproot. Stems are prostrate, short pubescent to almost glabrous, and up to 6 feet in length. The stems are green or reddish in color. Leaves are alternate, petiolate, bi-pinnately compound, with 4-5 pairs of pinnae each with 9-15 pairs of leaflets. Leaflets are oblong, entire, and ciliate. Like some species of Mimosa, the leaves of Yellow Puff will fold when touched or at night. Flowers are produced in ovoid or cylindrical heads from the axils of the leaves. Each head has 30-60 flowers, the upper flowers are perfect and fertile and the lower flowers are staminate. In bud the flower heads resemble unripe blackberries or mulberries. Each individual flower has five tiny yellow petals and ten yellow stamens. The fruit is a flattened, oblong legume.

Habitat ⁶

(2) Dry sandy areas, prairies, woodlands and creek valleys. Normally grows in dry sandy areas. Found scattered or locally frequent over the eastern half of Texas south to Aransas and the western half of Louisiana. It is reported from Alabama, Mississippi, Arkansas, Oklahoma, Texas, and Louisiana.
(3) Yellow Puff occurs in prairies, on chalk outcrops, in cedar glades, and on roadsides.