Luina

Luina
Silverback
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Asterids
Order:	Asterales
Family:	Asteraceae
Tribe:	Senecioneae
Genus:	Luina Benth., (1873)
Species
See text.

Luina, commonly called silverback, is a small genus of perennial shrubs in the sunflower family (Asteraceae).

The name of this genus is an anagram of the flower genus Inula.

Description

These are large, bushy perennials, native to the western and the northwestern states of the USA, growing on rock outcrops, cliffs, and talus slopes.

Their slender stems are covered with a gray, thick felt. They grow from a stout, branching, woody base, growing into clumps several meters across.

The leaves have an alternate arrangement, The leaf shape is lanceolate to ovate. The leaf margins are entire or dentate. The leaves are sessile in L. hypoleuca, but petiolate in L. serpentina. The leaves are glabrous above, but underneath thick with white hairs, giving it a silvery appearance. Hence its common name : silverback.

At the end of each stem there is an inflorescence with generally 4-12, flat-topped clustered flower heads. These are discoid, i.e. they contain only disc flowers and lack the ray flowers. The bracts under the flower head occur in 1-2 equal series. The receptacle is flat or convex.There are generally 11-23 bright yellow disc flowers, with a slightly expanded throat.

The glabrous or strigose fruit is 3-4 mm long. The pappus shows many bristles and is 8-10 mm long.^[1]

Species

• Luina hypoleuca Benth. : Silverback Luina, Littleleaf Luina
  • Luina hypoleuca var. californica (A. Gray)
  • Luina hypoleuca var. dentata L.F. Hend.
  • Luina hypoleuca var. hypoleuca
• Luina serpentina Cronquist : Colonial Luina, Creeping Silverback

References

External links

Media related to Luina at Wikimedia Commons