Chrysoma

Nuttall

J. Acad. Nat. Sci. Philadelphia 7: 67. 1834.

Etymology: Greek chrysos, gold, and - ome, having the condition of alluding to predominantly yellow-gold heads and corymbs
Treatment appears in FNA Volume 20. Treatment on page 105. Mentioned on page 5, 96, 108.
Revision as of 20:26, 16 December 2019 by FNA>Volume Importer

Shrubs, 50–100 cm (evergreen), glabrous, resinous. Stems erect, branched. Leaves cauline; alternate; sessile; blades 1-nerved, oblanceolate to narrowly elliptic (bases sometimes attenuate), margins entire, faces gland-dotted, resinous (covered by reticulum of subisodiametric areoles, each areole surrounded by sunken border). Heads usually radiate, sometimes discoid, in dense (terminal), cymiform arrays. Involucres cylindric, (5–6 ×) 2–2.5 mm. Phyllaries 8–12 in 3–4(–5) series (in vertical ranks), erect, loose, stamineous, 1-nerved (midnerves orange-resinous from bases to apices; flat), lanceolate, unequal, margins scarious. Receptacles flat, shallowly pitted, epaleate. Ray florets (0–)1–2(–3), pistillate, fertile; corollas yellow. Disc florets (2–)3–4(–5), bisexual, fertile; corollas yellow, tubular-funnelform, tubes longer than throats, lobes 5, spreading-recurving, lanceolate; style-branch appendages linear-triangular (closely papillate). Cypselae (brownish) turbinate-oblong, nearly terete, 8–10-ribbed, densely strigoso-sericeous; pappi persistent, of 40–60 tan, unequal, barbellate, apically attenuate bristles in 2–3 series. x = 9.

Distribution

se United States.

Discussion

Species 1.

Chrysoma pauciflosculosa was originally described within Solidago; it is distinct in anatomy (F. E. Lloyd 1901; K. Phillips 1963; L. C. Anderson and J. B. Creech 1975) and other features. Chrysoma is recognized by its shrubby habit, areolate-resinous leaves, corymbiform arrays of glomerate, cylindric, few-flowered heads, long disc corolla lobes, and papillate style-branch appendages.

Selected References

None.