Bigelowia

de Candolle in A. P. de Candolle and A. L. P. P. de Candolle

in A. P. de Candolle and A. L. P. P. de Candolle, Prodr.5: 329. 1836

Common names: Rayless-goldenrod
Etymology: For Jacob Bigelow, 1787–1879, Massachusetts medical and botanical scholar
Synonyms: Chondrophora
Found in FNA Volume 20. Treatment on page 95. Mentioned on page 5, 96.
Subshrubs, 30–70 cm (cespitose or colonial; caudices fibrous-rooted, short rhizomes or basal offsets). Stems erect, often subscapiform, early viscid, glabrous. Leaves basal (persistent rosettes); alternate; sessile; blades (3-nerved) linear to oblanceolate or spatulate, 4–14 cm, margins entire, faces gland-dotted (in pits); cauline linear, bractlike, abruptly or progressively reduced distally. Heads discoid, (in glomerate clusters) in compact to open, flat-topped, corymbiform arrays. Involucres cylindro-turbinate to cylindric, (4.5–9 ×) ca. 2 mm. Phyllaries 10–20 in 3–4 series, in vertical ranks, appressed (yellowish, sometimes green-tipped), 1-nerved (midnerves barely evident; weekly keeled) narrowly lanceolate to nearly linear, unequal, margins narrowly scarious, abaxial faces glabrous. Receptacles flat, pitted, epaleate. Ray florets 0. Disc florets 2–6, bisexual, fertile; corollas yellow, tubular, tubes shorter than or subequal to throats, lobes 5, recurved, lanceolate; style-branch appendages lanceolate. Cypselae turbinate to subcylindric, sometimes slightly compressed to nearly quadrate, 4–5-nerved (nerves thin, resinous), sparsely strigose; pappi persistent, of 40–50, tan, unequal, barbellate, apically attenuate bristles in 1(–2) series. x = 9.

Distribution

se United States.

Discussion

Species 2 (2 in the flora).

Bigelowia is recognized by its leaves basally disposed or in basal rosettes, slender, subscapiform stems, and densely corymbiform arrays of small, cylindro-turbinate, discoid heads with phyllaries in vertical ranks and yellow corollas. Karyotypes of Bigelowia species, as well as various floral features, resemble those of Euthamia (L. C. Anderson 1970, 1972), and a hypothesis of relationship has been tentatively confirmed by molecular evidence (M. A. Lane et al. 1996). G. L. Nesom (1994) placed Bigelowia closest to Chrysoma, Euthamia, Gundlachia, and Xylothamia on the basis of morphologic evidence.

Key

1 Plants with rhizomes or crowns, sometimes enlarging by offsets from stem/caudex bases; leaves linear-oblanceolate to oblanceolate or narrowly spatulate, 2–14 mm wide, bases not persistent Bigelowia nudata
1 Plants with rhizomelike caudex branches (becoming colonial or loosely matted); leaves linear, 1–2 mm wide, bases persistent (± sheathing branches of caudices) Bigelowia nuttallii
Facts about "Bigelowia"
AuthorGuy L. Nesom +
Common nameRayless-goldenrod +
EtymologyFor Jacob Bigelow, 1787–1879, Massachusetts medical and botanical scholar +
IllustratorBarbara Alongi +
Referenceanderson1970a +, anderson1972b + and anderson1977a +
SynonymChondrophora +
Taxon nameBigelowia +
Taxon parentAsteraceae tribe Astereae +
Taxon rankgenus +
VolumeVolume 20 +