Youngia japonica |
Youngia |
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oriental false hawksbeard |
youngia |
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Habit | Annuals, biennials [perennials], (10–)20–90+ cm; taprooted. | |
Stems | terete, fistulose. |
1–5+, erect (often scapiform), usually branched distally, sometimes throughout, proximally glabrous, puberulent, or tomentose. |
Leaves | petioles 1–10 cm, glabrous, puberulent, or densely hairy (hairs often brownish, crinkled); blades 3–12(–25) × 2–4(–6) cm, lateral lobes 0–20, mostly gradually reduced proximally, terminal lobes elliptic, ovate, obovate, or oblong-truncate, larger than laterals, apices obtuse or acute. |
all or mostly basal; petiolate (petiole bases often dilated, ± clasping); blades oblong or ovate to oblanceolate, margins usually pinnately lobed (± lyrate), ultimate margins denticulate. |
Peduncles | 1–5(–15) mm. |
(filiform) not distally inflated, seldom bracteate. |
Involucres | cylindric to campanulate, 2–3+ mm diam. |
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Receptacles | flat to convex, ± pitted, glabrous, epaleate. |
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Florets | corollas mostly 4.5–6.5 mm; anthers dark green (drying purplish); styles and style-branches yellow. |
8–25+; corollas yellow, sometimes abaxially purplish (anther bases with linear, acute auricles). |
Phyllaries | 3.5–6 mm, bases and midribs becoming ± spongy, abaxial faces glabrous, glabrate, or hairy (hairs appressed, shining). |
usually 8 in 1–2 series, lanceolate to linear, ± equal (reflexed in fruit), margins ± scarious, apices obtuse to acute. |
Calyculi | of 3–5+, deltate to ovate (membranous) bractlets. |
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Heads | (4–150) in corymbiform to paniculiform arrays. |
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Cypselae | 1.5–2.5 mm, bases hollow, lightly calloused; pappi 2.5–3.5 mm, slightly surpassing phyllaries. |
± reddish brown, ± fusiform and compressed [± terete], weakly or not beaked, ribs 11–13, ± spiculate to scabrellous on ribs; pappi (borne on discs at tips of cypselae) persistent (fragile) [falling], of 40–60+, basally coherent [distinct], white [yellowish or grayish], subequal, smooth to barbellulate bristles in ± 1 series. |
x | = 5 or 8. |
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2n | = 16. |
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Youngia japonica |
Youngia |
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Phenology | Flowering spring–summer (year-round south). | |
Habitat | Waste places, lawns, etc. | |
Elevation | 0–2400 m (0–7900 ft) | |
Distribution |
AL; AR; DC; FL; GA; KY; LA; MD; MS; NC; NY; PA; SC; TN; TX; VA; se Asia [Introduced in North America; introduced also in Mexico, Central America, South America, Europe, Africa, Pacific Islands, Australia]
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Asia [Introduced in North America; introduced also in South America, Europe, Africa, Pacific Islands, Australia] |
Discussion | Youngia japonica is now considered a pantropical weed. Relatively few specimens in the flora match what Babcock and Stebbins called subsp. elstonii, with cauline leaves almost as large as the basal and with conspicuous, lobed bracts at the bases of the proximalmost branches of the capitulescence. In subsp. japonica, to which most of our specimens are referred, the cauline leaves are much reduced or lacking, as are the bracts of the capitulescence. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species ca. 30 (1 in the flora). Youngia americana Babcock (based on a specimen from Alaska) has not been used as an accepted name for plants in the flora area; it was treated as a synonym of Crepis nana var. lyratifolia (Turczaninow) Hultén by E. Hultén (1968). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 19, p. 256. | FNA vol. 19, p. 255. |
Parent taxa | Asteraceae > tribe Cichorieae > Youngia | Asteraceae > tribe Cichorieae |
Subordinate taxa | ||
Synonyms | Prenanthes japonica, Crepis japonica, Y. japonica subsp. elstonii | |
Name authority | (Linneaus) de Candolle: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 7: 194. (1838) | Cassini: Ann. Sci. Nat. (Paris) 23: 88. (1831) |
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