Marshallia

Schreber

Gen. Pl. 2: 810. 1791.

Common names: Barbara’s buttons
Etymology: For Moses Marshall, 1758–1813, American botanist, nephew of and assistant to Humphrey Marshall
Treatment appears in FNA Volume 21. Treatment on page 456.

Perennials, (10–)20–80(–120) cm (fibrous-rooted, usually with caudices, sometimes rhizomatous). Stems erect, sometimes branched (striate). Leaves basal and/or cauline; alternate; petiolate or sessile; blades (1- or 3-nerved) elliptic, linear, linear-elliptic, linear-oblanceolate, oblanceolate, ovate, or spatulate, margins entire, faces glabrous. Heads discoid, borne singly or in open, corymbiform arrays (peduncles relatively long). Involucres hemispheric to obconic, 10–25+ mm diam. Phyllaries persistent, 12–24 in ± 2 series (lanceolate, linear, oblong, ovate, or rhombic, subequal, herbaceous, midnerves often keeled, proximal margins often scarious). Receptacles conic or convex (usually hollow), paleate (paleae linear to spatulate, distally herbaceous). Ray florets 0. Disc florets (20–)45–90(–160+), bisexual, fertile; corollas pale lavender, pink, or purple, or white, (usually hairy) tubes longer than to nearly equaling throats, lobes 5, lance-linear to linear-oblong (often contorted). Cypselae turbinate or clavate (5-angled, ribs 10, often hairy); pappi persistent, of 5(–6) scarious to membranous (hyaline, sometimes scaberulous) scales. x = 9.

Distribution

s, c, se United States.

Discussion

Species 7 (7 in the flora).

Key

1 Leaves lance-elliptic, lance-linear, linear, or oblanceolate (lengths mostly 13–30 times widths), widths mostly 2–13 mm > 2
1 Leaves elliptic, lanceolate, oblanceolate, ovate, or spatulate (lengths mostly 3–13 widths), widths 8–33 mm > 4
2 Corollas usually pale lavender to purple, rarely white; flowering Aug–Sep Marshallia graminifolia
2 Corollas usually white, sometimes pale lavender; flowering May–Jun > 3
3 Heads 4–10, 10–25 mm diam Marshallia ramosa
3 Heads borne singly, 20–32 mm diam Marshallia caespitosa
4 Leaves mostly cauline, blades ovate Marshallia trinervia
4 Leaves mostly basal, blades elliptic, lanceolate, oblanceolate, or spatulate > 5
5 Phyllary apices obtuse; corollas white Marshallia obovata
5 Phyllary apices acute; corollas pink > 6
6 Heads 1(–2), 26–45 mm diam Marshallia grandiflora
6 Heads 2–5(–10), 22–37 mm diam Marshallia mohrii
... more about "Marshallia"
Linda E. Watson +
Schreber +
Barbara’s buttons +
s +, c +  and se United States. +
For Moses Marshall, 1758–1813, American botanist, nephew of and assistant to Humphrey Marshall +
channell1957a +  and watson1990a +
Compositae +
Marshallia +
Asteraceae (tribe Heliantheae) subtribe Marshalliinae +