Tonestus lyallii
Encyclopedia
Tonestus lyallii is a species of flowering plant in the aster family
known by the common names Lyall's goldenweed and Lyall's serpentweed. It is native to western North America, particularly in the Rocky Mountains
and the mountain ranges of the Pacific Northwest
with scattered occurrences between. It is a perennial herb growing in clumps or short bunches not more than about 15 centimeters tall, the stem branching from a tough caudex
. The leaves are smooth-edged and linear or lance-shaped, the largest at the base of the plant reaching up to about 8 centimeters long. The inflorescence
is a single flower head
or a pair of heads each about a centimeter wide with green or red phyllaries
. The head bears at least 10 or 11 bright yellow ray florets around a center containing many tubular disc florets.
Asteraceae
The Asteraceae or Compositae , is an exceedingly large and widespread family of vascular plants. The group has more than 22,750 currently accepted species, spread across 1620 genera and 12 subfamilies...
known by the common names Lyall's goldenweed and Lyall's serpentweed. It is native to western North America, particularly in the Rocky Mountains
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...
and the mountain ranges of the Pacific Northwest
Pacific Northwest
The Pacific Northwest is a region in northwestern North America, bounded by the Pacific Ocean to the west and, loosely, by the Rocky Mountains on the east. Definitions of the region vary and there is no commonly agreed upon boundary, even among Pacific Northwesterners. A common concept of the...
with scattered occurrences between. It is a perennial herb growing in clumps or short bunches not more than about 15 centimeters tall, the stem branching from a tough caudex
Caudex
A caudex is a form of stem morphology appearing as a thickened, short, perennial stem that is either underground or near ground level . It may be swollen for the purpose of water storage, especially in xerophytes...
. The leaves are smooth-edged and linear or lance-shaped, the largest at the base of the plant reaching up to about 8 centimeters long. The inflorescence
Inflorescence
An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Strictly, it is the part of the shoot of seed plants where flowers are formed and which is accordingly modified...
is a single flower head
Head (botany)
The capitulum is considered the most derived form of inflorescence. Flower heads found outside Asteraceae show lesser degrees of specialization....
or a pair of heads each about a centimeter wide with green or red phyllaries
Bract
In botany, a bract is a modified or specialized leaf, especially one associated with a reproductive structure such as a flower, inflorescence axis, or cone scale. Bracts are often different from foliage leaves. They may be smaller, larger, or of a different color, shape, or texture...
. The head bears at least 10 or 11 bright yellow ray florets around a center containing many tubular disc florets.