[Illustration: SAMPSON’S ROOT. PURPLE CONE-FLOWER]
Sampson’s Root. Narrow-Leaved Purple Cone-Flower (_Echinachea angustifolia_) is easily recognized by the spreading or somewhat drooping rose-colored rays. The heads terminate the stiff, unbranched stems which, like the narrow leaves, are very rough and bristly. The stems grow one to two feet high and are scattered on limestone hillsides but may occasionally be found in dense patches along the roadsides. The leaves have three prominent nerves.
The scientific name is derived from the Greek and refers to the stiff reddish-brown chaff on the flower head. This chaff obscures the brown disk flowers and remains on the heads long after the seeds have fallen. This plant is hard to distinguish from the pale purple cone-flower (_Echinachea pallida_), which grows in the woods in the eastern part of the state. The latter has longer and more drooping ray flowers. The purple cone-flowers are well known in cultivation.
[Illustration: RAGWEED. LYRE-LEAVED PARTHENIUM]
Ragweed. Lyre-Leaved Parthenium (_Parthenium lyratum_) blooms from early spring until fall in Southwest Texas. This is a smaller plant than the common parthenium (_Parthenium hysterophorus_), which is widespread in the Gulf States and tropical America. The latter is a widely branched plant two to three feet high and grows in dense masses. They have similar flower clusters with small heads of greenish-white flowers. Neither of these is the ragweed or bloodweed commonly associated with hay fever; however, the common parthenium is listed as a poisonous plant. Wild quinine or feverfew (_Parthenium integrifolium_), used as a pioneer drug to relieve fever, has been reported from the state.
Several shrubby partheniums are found in West Texas. The most important member of the group is the silver-leaved guayule or rubber plant (_Parthenium argentatum_), found in West Texas and Mexico. It is a commercial source of rubber but is not yet profitable, as the plants are of slow growth.
Common Sunflower (_Helianthus annuus_) has been known in cultivation for many years but is considered native from Minnesota to Texas and Mexico. It is the state flower of Kansas. The stout, erect stems are widely branched above the base and are very sticky, 2-10 feet high. The flower heads, 3-6 inches broad, have many yellow ray flowers about an inch long and numerous tubular disk flowers. It is grown commercially for its fiber and seeds. The seeds make an excellent food for poultry and furnish an oil used in making soap, candles, and salad dressing.