Annuals, biennials, or perennials (sometimes aromatic), (4–)15–150(–200) cm (usually taprooted, sometimes fibrous-rooted). Stems 1+, usually erect, sometimes decumbent to procumbent (± woolly-tomentose, sometimes stipitate- or sessile-glandular). Leaves basal and cauline or mostly cauline; alternate; usually sessile; blades mostly narrowly lanceolate to oblanceolate, bases often clasping and/or decurrent, margins entire, faces bicolor or concolor, abaxial white to gray and tomentose to velutinous, adaxial usually greenish and glabrous or glabrescent, sometimes grayish and loosely arachnose (sometimes stipitate- or sessile-glandular). Heads disciform, usually in glomerules in corymbiform or paniculiform arrays, sometimes in terminal clusters. Involucres mostly campanulate to cylindric, (3–)4–7 mm. Phyllaries in (2–)3–7(–10) series, whitish, rosy, tawny, or brownish (opaque or hyaline, dull or shiny; stereomes usually green, usually sessile-glandular distally), unequal, usually chartaceous toward tips. Receptacles flat, smooth, epaleate. Peripheral (pistillate) florets (15–)25–250+ (more numerous than bisexual); corollas yellowish. Inner (bisexual) florets (1–)5–20(–40+); corollas yellowish (red-tipped in P. luteoalbum). Cypselae oblong-compressed or cylindric, faces usually smooth, sometimes papillate-roughened and/or with 4–6 longitudinal ridges, usually glabrous (papilliform hairs in P. luteoalbum); pappi readily falling, of 10–12 distinct (coherent basally in Pseudognaphalium luteoalbum and P. stramineum), barbellate bristles in 1 series. x = 7.

Distribution

Worldwide, mostly South America to North America, mostly in temperate regions.

Discussion

Species ca. 100 (21 in the flora).

Fifteen of the species treated here occur also in Mexico; those that do not are Pseudognaphalium obtusifolium, P. saxicola, P. micradenium, and P. helleri (eastern United States and adjacent Canada), and P. ramosissimum and P. thermale (western United States and adjacent Canada).

Basal and proximal leaves of Pseudognaphalium species often wither before plants reach flowering. In the key and descriptions here, references to leaves are to cauline leaves of plants at flowering unless otherwise indicated.

Selected References

Nesom, G. L. 2004d. Pseudognaphalium canescens (Asteraceae: Gnaphalieae) and putative relatives in western North America. Sida 21: 781–790.

Lower Taxa

Pseudognaphalium arizonicum, Pseudognaphalium austrotexanum, Pseudognaphalium beneolens, Pseudognaphalium biolettii, Pseudognaphalium californicum, Pseudognaphalium canescens, Pseudognaphalium helleri, Pseudognaphalium jaliscense, Pseudognaphalium leucocephalum, Pseudognaphalium luteoalbum, Pseudognaphalium macounii, Pseudognaphalium micradenium, Pseudognaphalium microcephalum, Pseudognaphalium obtusifolium, Pseudognaphalium pringlei, Pseudognaphalium ramosissimum, Pseudognaphalium roseum, Pseudognaphalium saxicola, Pseudognaphalium stramineum, Pseudognaphalium thermale, Pseudognaphalium viscosum

Key

1	Leaf faces strongly to weakly bicolor (abaxial gray to white, tomentose, adaxial green, not tomentose, sometimes glandular)	> 2
1	Leaf faces concolor or weakly bicolor (both usually gray to gray-green or greenish, tomentose, adaxial sometimes glandular beneath tomentum)	> 10
2	Bases of leaf blades not clasping, not decurrent	> 3
2	Bases of leaf blades clasping and/or decurrent	> 5
3	Stems white (tomentose, rarely glandular near bases); pistillate florets 38–96; bisexual florets 4–8(–11)	Pseudognaphalium obtusifolium
3	Stems greenish (lacking or soon losing most tomentum, usually densely stipitate-glandular); pistillate florets 47–107; bisexual florets 7–20	> 4
4	Stems glandular-villous (stipitate glands mostly 0.3–1 mm, variable in height on any portion of stem, stalks broadened toward bases, about equaling gland widths); leaf blades mostly oblong-lanceolate, 2.5–7 cm × 4–20 mm; pistillate florets 83–107; bisexual florets 9–15	Pseudognaphalium helleri
4	Stems glandular-puberulent (stipitate glands 0.1–0.2 mm, stalks narrower than gland widths); leaf blades linear to linear-lanceolate or linear-oblanceolate, 1.5–5.5 cm × 1.5–10 mm; pistillate florets 47–78; bisexual florets (7–)11–20	Pseudognaphalium micradenium
5	Leaves crowded (internodes usually 1–3, sometimes to 10 mm), blades linear to linear-lanceolate, margins strongly revolute	> 6
5	Leaves not crowded (internodes mostly more than 5 mm), blades elliptic, elliptic-ovate, lanceolate, oblanceolate, or oblong, margins flat or slightly revolute	> 8
6	Phyllaries bright white, opaque, dull; cypselar faces smooth	Pseudognaphalium leucocephalum
6	Phyllaries tawny to silvery white, ± hyaline, shiny; cypselar faces papillate-roughened	> 7
7	Stems stipitate-glandular; leaf bases not subclasping (proximal usually decurrent 3–10 mm); phyllaries ovate-lanceolate (apices of inner not thickened along midribs, not apiculate); pistillate florets ca. 200–250; bisexual florets (13–)16–29	Pseudognaphalium viscosum
7	Stems not glandular; leaf bases subclasping (not decurrent); phyllaries narrowly ovate to oblong or elliptic (apices of inner thickened and slightly raised along midribs, apiculate); pistillate florets [46–]76–102; bisexual florets (6–)8–11	Pseudognaphalium austrotexanum
8	Stems not glandular; leaf bases auriculate-clasping, faces strongly bicolor	Pseudognaphalium biolettii
8	Stems glandular; leaf bases weakly, if at all, clasping, faces strongly to weakly bicolor	> 9
9	Involucres 4.5–5.5 mm; phyllaries in 4–5 series; bisexual florets 7–12	Pseudognaphalium macounii
9	Involucres 3.5–4 mm; phyllaries in 2–3 series; bisexual florets (1–)2–6	Pseudognaphalium pringlei
10	Leaf bases clasping to subclasping, seldom decurrent (decurrent 1–2 mm in P. luteoalbum and P. stramineum, 2–10 mm in P. californicum)	> 11
10	Leaf bases not clasping or subclasping, decurrent or not	> 14
11	Heads in terminal glomerules; involucres 3–6 mm; phyllaries silver-gray to yellowish (hyaline); pistillate florets 135–160 (pappus bristles loosely coherent basally, released in clusters or easily fragmented rings)	> 12
11	Heads in corymbiform arrays; involucres 4–7 mm; phyllaries usually silvery white to white, sometimes pink (mostly opaque); pistillate florets 35–140 (pappus bristles not coherent basally, released singly)	> 13
12	Involucres 3–4 mm; bisexual florets 5–10 (corollas red-tipped; cypselae with papilliform hairs)	Pseudognaphalium luteoalbum
12	Involucres 4–6 mm; bisexual florets mostly 18–28 (corollas evenly yellowish, not red-tipped; cypselae glabrous)	Pseudognaphalium stramineum
13	Stems stipitate-glandular; abaxial faces of leaf blades green, stipitate- glandular; phyllaries in 7–10 series	Pseudognaphalium californicum
13	Stems not glandular; abaxial faces of leaf blades white-tomentose or woolly- tomentose; phyllaries in 5–6 series	Pseudognaphalium roseum
14	Leaf bases not decurrent	> 15
14	Leaf bases decurrent	> 17
15	Annuals 4–15(–30) cm; faces of leaf blades concolor, green, thinly arachnoid-tomentose to glabrate, not glandular (veiny reticulum evident); heads in terminal capitate clusters; cypselae smooth	Pseudognaphalium saxicola
15	Annuals, biennials, or perennials, 20–100+ cm; faces of leaf blades concolor or weakly bicolor, white to gray, ± tomentose, sometimes glandular beneath tomentum; heads in corymbiform arrays; cypselae smooth or papillate-roughened	> 16
16	Adaxial faces of leaf blades sometimes sessile-glandular beneath adaxial tomentum; involucres 4–5 mm; phyllaries in 3–4 series; bisexual florets (1–)2–5(-6)	Pseudognaphalium canescens
16	Adaxial faces of leaf blades not glandular; involucres 5–6 mm; phyllaries in 4–6 series; bisexual florets 5–9	Pseudognaphalium microcephalum
17	Stems and leaves stipitate-glandular; heads in corymbiform or paniculiform arrays; phyllaries usually white or pinkish, sometimes greenish	> 18
17	Stems and leaves not glandular; heads usually in corymbiform or paniculiform arrays (sometimes borne singly or in glomerules in P. arizonicum); phyllaries usually white, whitish, or brownish to tawny, rarely rosy	> 19
18	Leaf blades mostly narrowly oblong-lanceolate, 5–10(–20) mm wide; heads in corymbiform arrays; involucres campanulo-globose; phyllaries in 7–10 series, white	Pseudognaphalium californicum
18	Leaf blades linear to lanceolate, oblong, or narrowly spatulate, 3–5(–7) mm wide; heads in paniculiform (usually elongate to broadly columnar) arrays; involucres turbinate to short-cylindric; phyllaries in 4–5 series, usually pinkish, sometimes white to greenish	Pseudognaphalium ramosissimum
19	Phyllaries usually brownish to tawny, rarely rosy, ovate-lanceolate to lanceolate (hairs of stems and leaves commonly with reddish or purplish cross walls).	Pseudognaphalium arizonicum
19	Phyllaries white or whitish, ovate to ovate-oblong (hairs of stems and leaves without colored cross walls)	> 20
20	Pistillate florets 80–115[–180]; bisexual florets (6–)8–12[–30] (bases of hairs on leaves persistent, enlarged)	Pseudognaphalium jaliscense
20	Pistillate florets 35–69; bisexual florets 3–8(–11) (bases of hairs on leaves not persistent and enlarged)	> 21
21	Blades of basal and proximal cauline leaves linear (proximal and distal similar in size and shape); heads usually in paniculiform arrays; phyllaries in (4–)5–6(–7) series (usually opaque, dull to shiny)	Pseudognaphalium beneolens
21	Blades of basal and proximal cauline leaves linear-oblanceolate (the distal shorter and narrower); heads in corymbiform to paniculiform arrays; phyllaries in 3–4(–5) series, hyaline or opaque, usually shiny, sometimes dull	Pseudognaphalium thermale