Picris hieracioides L., Asteraceae

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Present on Pacific Islands?  yes

Primarily a threat at high elevations?  no

Other Latin names:  Picris japonica Thunb.; Picris longifolia Boiss. & Reut.

Common name(s): [more details]

Chinese: mao lian cai

English: hawkweed, hawkweed oxtongue

Habit:  herb

Description:  "Perennial, c. 80 cm high, stem slightly ribbed lengthwise, diameter more than 3.0 mm, moderately branched near apex.  Indumentum of stem moderate to dense, on leaves dense, of mainly 2-hooked anchor hairs, 1.3-2.1 mm long, size and density of hairs decreasing towards apex of plant or constant on whole stem; leaves densely hairy with slender to needlelike anchor hairs.  Basal leaves many, 10-(-15 or longer?) cm long, 1.3 cm wide, lanceolate, strongly dentate, petiolate.  Stem leaves lanceolate to narrowly obovate, petiolate near base, gradually becoming smaller and sessile towards apex of plant; lower stem leaves 6-15 cm long, 1.5-2.2 cm wide, dentate; terminal stem leaves lanceolate to bract-like, 0.5-1.2 cm long, 0.2-0.3 cm wide.  Rosette leaves persisting through fruiting stage.  Peduncles 1.5-2 cm (or more?) long, moderately tomentose, densely hairy with 2-hooked anchor hairs, hairs up to 0.8 mm long; peduncles with 4-7 bracts near capitulum of similar shape and indumentum as outer involucral bracts, bracts squarrose, appearing to descend from involucrum.  Capitula c. 10-15 in corymbose panicle, flowering 0.9-1.1 cm long, 0.7-0.9 cm in diameter, fruiting 0.9-1.1 cm long, 0.8-1.1 cm in diameter.  Involucrum of c. 30 bracts in 3 irregular outer and 2 inner rows, outer bracts squarrose to recurved, becoming more upright towards inner rows.  Inner bracts of flowering capitulum up to 1/3 longer than outer bracts.  All bracts of mature capitula slightly succulent, pubescent, moderately, on tips and margin more densely tomentose.  A double or triple, complete to incomplete line of slender to needle-like 2-hooked anchor hairs and bifid forked hairs along midrib on abaxial side of at least the inner bracts present, length of hairs 0.8-1.0 mm, outer bracts sometimes naked or with hairs in a single line.  Outermost bracts of mature capitula c. 3.4 mm long, c. 0.7 mm wide, longest outer bracts 4.5-5.0 mm long, 1.0-1.3 mm wide; inner bracts 9.0-11.0 mm long, 2.1-2.2 mm wide, outer bracts lanceolate to obovate, inner bracts lanceolate.  Midrib of inner involucral bracts thickened in fruiting stage, no opened involucrum seen.  Capitula with c. 30-50 flowers, corolla 12.2 mm long, ligule 8.4 mm long, not fully opened on flowers examined, apical teeth of ligule 0.2-0.5 mm long, corolla tube 3.8 mm long, anther tube 3.7 mm long, apical appendages of anthers 0.4 mm long, basal appendages 0.7 mm long; style 9.9 mm long, style branches 1.4 mm long.  Achenes fusiform with largest diameter near the distal end, abruptly ending into a minute cuspis; 3.2-4.1 mm long, c. 0.8 mm in diameter, length of cuspis 0.1-0.2 mm, c. 1/20-1/32 of total length of achene.  Number of ribs per achene segment c. 38-40, per mm achene length c. 9.5-11.8; scales small, flat.  Pappus 5.0-5.9 mm long, pappus rays c. 40-50.  Receptacle not seen"  (Holtzapfel, 1994; p. 188).

"Biennial or short-lived perennial herbs, densely hirsute or hispid, many of the hairs branched.  Leaves often quickly deciduous, oblanceolate to lanceolate or oblong, 7-30 cm long, 0.5-5 cm wide, usually abruptly reduced in upper part of stem.  Involucre 0.8-1.5 cm high, the bracts in 2 series, inner ones subequal, outer ones shorter; pappus of plumose capillary bristles, readily deciduous as a unit.  Achenes longitudinally grooved, rugose, 3.5-6 mm long, narrowed above or with a very short beak"  (Wagner et al., 1999; p. 350).

Description from the Flora of China online.
Description from the Flora of North America online.

Habitat/ecology:  In Hawai‘i, "naturalized in relatively dry areas"  (Wagner et al., 1999; p. 350).  In China (native), "grasslands, mountain slopes, forests, along ditches, fields, wastelands, sandy soils; 200-3600 m"  (Flora of China online).

Propagation:  Seed

Native range:  Eurasia  (Wagner et al., 1999; p. 350).

Presence:

Pacific
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Australia (Pacific offshore islands) Norfolk Islands	Norfolk Island	introduced invasive	Australian Biological Resources Study (2013)
State of Hawaii Hawaiian Islands	Hawai‘i (Big) Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 350)
State of Hawaii Hawaiian Islands	Lāna‘i Island	introduced invasive	Wagner, Warren L./Herbst, Derral R./Sohmer, S. H. (1999) (p. 350) Voucher cited: Munro 540 (BISH)
State of Hawaii Hawaiian Islands	Maui Island	introduced invasive	Oppenheimer, Hank (2013) (p. 17) Voucher cited: Oppenheimer . H21005 (BISH, PTBG)
State of Hawaii Hawaiian Islands	Moloka‘i Island	introduced invasive	Oppenheimer, Hank (2008) (p. 24) Vouchers cited: Oppenheimer & Perlman H80705 (BISH, PTBG), Oppenheimer & Perlman H80708 (BISH, PTBG)

Pacific Rim
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
British Columbia (province of Canada) Province of British Columbia	Canada (British Columbia)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
China China	China (People's Republic of)	native	Zhengyi, Wu/Raven, Peter H./Deyuan, Hong (2013)
Japan Japan	Japan	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
North Korea North Korea	North Korea (Democratic People's Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
South Korea South Korea	South Korea (Republic of)	native	U.S. Dept. Agr., Agr. Res. Serv. (2013)
New Zealand New Zealand	New Zealand (country)	possibly native	Allan, H. H. (1982) (p. 759)
Taiwan Taiwan Island	Taiwan Island	native	Ching-I Peng, ed. (2013) subsp. morrisonensis (Hayata) Kitam., "open roadside and meadows, 1,500-3,500 m"; subsp. ohwiana (Kitam.) Kitam., "above 3,400 m".
United States (west coast) United States (west coast states)	USA (Washington)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Also reported from
Country/Terr./St. & Island group	Location	Cited status & Cited as invasive & Cited as cultivated & Cited as aboriginal introduction?	Reference & Comments
Canada Canada	Canada	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)
United States (continental except west coast) United States (other states)	United States (other states)	introduced	U.S. Dept. Agr., Nat. Res. Cons. Serv. (2013)

Control:  If you know of control methods for Picris hieracioides, please let us know.