Helianthus bolanderi is a species of sunflower known by the common names Bolander's sunflower[1] and serpentine sunflower.[2] It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. It has been found from southwestern Oregon as well as in northern and central California as far south as Santa Cruz County, with reports of a few isolated populations in southern California (some of them from urban areas and very likely cultivated or escaped specimens).[3][4]
This wild sunflower is an erect annual reaching heights over a meter (40 inches). It has a hairy, rough stem with leaves lance- or oval-shaped, usually pointed, sometimes serrated along the edges, and 3 to 15 centimeters (1.2-6.0 inches) long. The inflorescence holds one or more flower heads, and each plant may have many inflorescences growing along the full length of the stem. The flower head has a cup of long, pointed phyllaries holding an array of bright yellow ray florets each one to two centimeters (0.4-0.8 inches) long around a center of yellow to dark purple or reddish disc florets. The achene is 3 to 5 millimeters (0.12-0.20 inches) long.[5]
Helianthus bolanderi is a species of sunflower known by the common names Bolander's sunflower and serpentine sunflower. It is native to California and Oregon, where it grows mainly in mountainous areas, often in serpentine soils. It has been found from southwestern Oregon as well as in northern and central California as far south as Santa Cruz County, with reports of a few isolated populations in southern California (some of them from urban areas and very likely cultivated or escaped specimens).
This wild sunflower is an erect annual reaching heights over a meter (40 inches). It has a hairy, rough stem with leaves lance- or oval-shaped, usually pointed, sometimes serrated along the edges, and 3 to 15 centimeters (1.2-6.0 inches) long. The inflorescence holds one or more flower heads, and each plant may have many inflorescences growing along the full length of the stem. The flower head has a cup of long, pointed phyllaries holding an array of bright yellow ray florets each one to two centimeters (0.4-0.8 inches) long around a center of yellow to dark purple or reddish disc florets. The achene is 3 to 5 millimeters (0.12-0.20 inches) long.
Helianthus bolanderi es una especie de girasol (Helianthus) silvestre, conocida en el oeste de Estados Unidos, su lugar de origen, como «Bolander's sunflower».
Es frecuentemente confundida con Helianthus exilis (llamado serpentine sunflower - por crecer generalmente en rocas de serpentina), con el cual comparte caracteres comunes, en particular en las escamas del receptáculo.[1]
El epíteto específico alude a Henry Nicholson Bolander (1831-1897), un botánico herborizando en California en 1864.[2]
Se trata de una especie anual que tiene una altura entre 60cm y 1,5m, con tallos erectos híspidos o hirsutos. Las hojas son principalmente caulinares y alternas, pecioladas. Dichas hojas tienen forma lanceolada-linear ovalada, y tienen 3-15cm por 2-6cm. La base es cuneada hasta truncada, y los bordes generalmente aserrados con la cara inferior algo hirsuta y glandulífera. Los receptáculos son hemiesféricos de 1,5-2,5cm de diámetro, con 10-15 brácteas involucrales usualmente lanceoladas con ápice gradualmente atenuado, y con la cara exterior hirsuta. Las escamas del receptáculo son tri-dentadas con sus ápices glabros, el diente mediano mucho más largo. Hay 12-15 lígulas amarillas con limbos de 1,5-2 cm de largo, y unos 75 o más flósculos, con los lóbulos habitualmente rojizos con las anteras negras. El fruto es un aquenio glabro o algo peludo, de color pardo oscuro y tiene de 3 a 4,5 mm de largo. El vilano está constituido por 2 escamas lanceoladas de 1,5-3mm.[1]
Florece desde el verano hasta principios del otoño.
Es una planta nativa de California (Klamath Ranges, cordillera costera de California, cordillera de las Cascadas, Sierra Nevada Foothills, valle Central de California, Área de la Bahía de San Francisco, cordillera costera de California) y Oregon (Estados Unidos), donde crece de 10 hasta 1.200 m de altitud en lugares principalmente herbosos, frecuentemente removidos.[1]
Helianthus bolanderi es una especie de girasol (Helianthus) silvestre, conocida en el oeste de Estados Unidos, su lugar de origen, como «Bolander's sunflower».
Es frecuentemente confundida con Helianthus exilis (llamado serpentine sunflower - por crecer generalmente en rocas de serpentina), con el cual comparte caracteres comunes, en particular en las escamas del receptáculo.
Helianthus bolanderi là một loài thực vật có hoa trong họ Cúc. Loài này được A.Gray mô tả khoa học đầu tiên năm 1865.[1]
Helianthus bolanderi là một loài thực vật có hoa trong họ Cúc. Loài này được A.Gray mô tả khoa học đầu tiên năm 1865.
