Hieracium lachenalii [Common Hawkweed]

[Andrea B.]

Blum, A. G. (2015) Hieracium lachenalii K.C. Gmel. (Asteraceae) Common Hawkweed. Flowers photographed in ultraviolet and visible light. http://www.ultraviol...ommon-hawkweed/

 

High Road, Southwest Harbor, Maine, USA

29 July 2014

Wildflower

 

Synonyms:

• Hieracium amitsokense Dahlstedt
  
• H. groenlandicum Arvet-Touvet
  
• H. ivigtutense Omang
  
• H. scholanderi Omang
  
• H. sylowii Omang
  
• Hieracium vulgatum Fr.
  

Comment:

The tapered leaf base on rosette leaves distinguishes H. lachenalii from H. murorum.

 

Reference:

1. New England Wild Flower Society (2015) Hieracium lachenalii K.C. Gmel. Common Hawkweed. https://gobotany.new...ium/lachenalii/

 

Equipment [Nikon D600-broadband + Carl Zeiss 60mm f/4.0 UV-Planar]

Unless otherwise noted.

 

Visible Light [f/7.1 for 1/500" @ ISO-800 with Nikon Df + Nikon 60mm f/2.8G Micro-Nikkor]

An impressive specimen of Common Hawkweed with large cluster of basal leaves.

 

Visible Light [f/9 for 1/200" @ ISO-800 with Nikon Df + Nikon 60mm f/2.8G Micro-Nikkor]

Tapered leaf base.

 

Visible Light [f/8 for 1/1250" @ ISO-100 with Nikon Df + Nikon 60mm f/2.8G Micro-Nikkor]

H. lachenalii against the skies over Somes Sound.

 

Ultraviolet Light [f/11 for 15" @ ISO-400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

Diffuse bullseye in UV.

 

Ultraviolet Light [f/11 for 15" @ ISO-400 with SB-14 UV-modified Flash and Baader UV-Pass Filter]

Abaxial view.

 

Visible Light [f/11 for 1.3" @ ISO-400 with onboard Flash and Baader UVIR-Block Filter]

Involucre with glandular hairs.

 

 

FNA | Family List | FNA Vol. 19, 20 and 21 | Asteraceae | Hieracium

26. Hieracium vulgatum Fries, Fl. Hall. 128. 1819.

Plants 30–60(–100+) cm.

Stems: proximally piloso-hirsute (hairs 1–3+ mm), distally stellate-pubescent and stipitate-glandular, sometimes piloso-hirsute as well (hairs 1–2+ mm).

Leaves: basal 3–8+, cauline 1–5+; blades (often purple-mottled) lance-elliptic to lanceolate, 50–100 × 10–50+ mm, lengths 2–5 times widths, bases usually cuneate, sometimes rounded to truncate, margins ± dentate or entire, apices acute, faces usually ± piloso-hirsute (at least near margins, hairs 1–3+ mm), sometimes glabrate.

Heads: (1–)3–9+ in corymbiform arrays.

Peduncles: stellate-pubescent and stipitate-glandular.

Calyculi: bractlets 13–16+.

Involucres: ± obconic, 8–10 mm.

Phyllaries: ca. 21+, apices acute to acuminate, abaxial faces stellate-pubescent and stipitate-glandular.

Florets: 40–80+; corollas yellow, 13–18 mm.

Cypsela: columnar, 2.5–3 mm; pappi of 30–40+, stramineous bristles in ± 2 series, ca. 5 mm.

Flowering: (Jun–)Jul–Aug. Disturbed sites, openings in thickets; 10–100+ m;

Greenland; B.C., N.B., Nfld. and Labr., N.S., Ont., P.E.I., Que.; Conn., Del., Maine, Mass., Mich., Minn., N.H., N.J., N.Y., Oreg., Pa., R.I., Vt., Wash., Wis.; Europe.

The correct name for the species here called Hieracium vulgatum may be H. lachenallii C. C. Gmelin (E. Lepage 1971; E. G. Voss 1972–1996, vol. 3). Plants of H. groenlandicum (stems mostly piloso-hirsute and not stipitate-glandular, corolla lobes distally ciliate) are sometimes treated as distinct from H. vulgatum in a narrow sense (stems usually stipitate-glandular and not piloso-hirsute, corolla lobes not ciliate distally).