Common name: Guernsey Fleabane
Scientific name: Erigeron sumatrensis 蘇門白酒草、野茼蒿 *
Genus: Erigeron 飛蓬屬
Family: Asteraceae or Compositae 菊科, aster , daisy, composite or sunflower family
Remarks*: It was formerly named Conza sumatrensis 蘇門白酒草, belonged to Conza 假蓬屬、白酒草屬. It is also recorded in Hong Kong as an exotic plant. '茼蒿' is pronounced as '朣 hou1' in Cantonese.
Origin: Neophyte (established after 1500 AD). I It is a native of South America. It was first recorded in 1961 and was found naturalized in 1974.
Date: 4th Aug
[051] Annual or biennial herbs, 50-100 cm tall.
[052] Stem erect.
[041] Middle and upper leaves subentire or shallowly toothed.
[042] Middle and upper leaves gradually smaller upward, lanceolate to linear.
[043] All leaves pubescent on both surfaces.
[044] Note the hairy stem and lower surface of the leaves.
[043_1] Lower surface of the leaf.
[044_1] Forward hairs on leaf margin.
[046] Leaves in lower part oblanceolate or lanceolate, 5–15 × 0.5–2.5 cm, base attenuate 漸狹, apex acute, margin coarsely toothed or subentire.
[027] A pair of stipules at the base of the leaf.
[029] Stems hirsute‑pubescent 粗毛兼被短柔毛的 throughout.
[029_1] Cropped photo above to show clearly the hairs.
[048] Stems hirsute‑pubescent 粗毛兼被短柔毛的 throughout. (Lower stem)
[048_1] Cropped photo above to show clearly the hairs.
[047] Basal leaves withered at flowering period. (Basal stem)
[047_1] Cropped photo above to show clearly the hairs.
[049] Capitula 頭狀花序 arranged in large panicle 圓錐花序.
[063]
[032] Flower buds.
[038]
[032_1] Flower buds.
[038_1] Flower heads (capitula 頭狀花序) 5-8 mm across, ray florets with brownish petals, involucral bracts densely hairy.
(vs flower heads 3-5 mm across, white petals of the ray florets, involucral bracts glabrous in Erigeron canadensis 小蓬草、加拿大蓬、飛蓬、小飛蓬, Canadian Fleabane)
(vs flower heads 7-11 mm across, flower head clearly red tipped, involucral bracts hairy in Erigeron bonariensis 香絲草、野茼蒿、美洲假蓬、野地黃菊、蓑衣草、消息草, Argentine fleabane)
(vs flower heads 3-5 mm across, flower head with tendency to purple tips, involucral bracts with few hairs in Erigeron floribunda 多花飛蓬、多花飛蓮, Bilbao fleabane)
[038_2] Heads 5-8 mm across, involucral bracts densely hairy
[014]
[056]
[014_1] Note there are 5 petals on disc florets. Ray florets pistillate 雌花的、具雌蕊的 and disk florets hermaphrodite.
[056_1] Note there are 5 petals on disc florets.(need to hold it in order to photo it clearly)
(vs 4-5 petals on disc florets in Erigeron canadensis 小蓬草、加拿大蓬、飛蓬、小飛蓬, Canadian Fleabane)
(vs 5 petals on disc florets in Erigeron bonariensis 香絲草、野茼蒿、美洲假蓬、野地黃菊、蓑衣草、消息草, Argentine fleabane and Erigeron floribunda 多花飛蓬、多花飛蓮, Bilbao fleabane)
[001] A possible pollinator -- a hoverfly belonged to Sphaerophoria 細腹食蚜蠅屬 spp, possibly a female Sphaerophoria scripta 短翅細腹食蚜蠅.