FNA: Eriophyllum lanatum vs. Eriophyllum lanatum var. achilleoides

Phenology

Flowering Apr–Jun.

Habitat

Dry sites, chaparral, forests

Elevation

30–1300 m (100–4300 ft)

Distribution

CA; ID; MT; NV; OR; UT; WA; WY; BC; Mexico (probably extinct)

[WildflowerSearch map]

[BONAP county map]

CA; NV; OR

Discussion

Varieties 10 (10 in the flora).

Eriophyllum lanatum is a polyploid complex of intergrading regional facies treated here as varieties. Artificial hybridization studies show that strong barriers to interbreeding exist among the varieties at the diploid level (J. S. Mooring 2001). In nature, morphologically intermediate polyploid populations often occur in regions where the ranges of the varieties approach one another. Edaphic factors and light intensity also make identification more difficult by strongly influencing leaf morphology and sizes of structures. For example, cultivated individuals of var. achillioides may have laciniately toothed rather than pinnatifid leaves. Rarely, plants of different varieties maintain their identity while growing side by side. In some instances, one is diploid and the other tetraploid; in others both are diploid. Varieties arachnoideum, croceum, grandiflorum, and obovatum apparently form natural hybrids with E. confertiflorum var. confertiflorum; past hybridizations may have resulted in the origin of E. latilobum and E. jepsonii (L. Constance 1937; P. A. Munz 1959; Mooring 1994) and E. confertiflorum var. tanacetiflorum (Mooring 1994).

Our treatment of Eriophyllum lanatum closely follows that of L. Constance (1937), which was done without benefit of cytogeographic studies. The key is to modal populations of the varieties, usually based on living plants.

Some varieties have been introduced into cultivation as ornamentals.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

In northern California, a taxonomically perplexing series of intermediate populations connects vars. arachnoideum, achillioides, and grandiflorum. Polyploiids characterize the regions where the varieties meet. Putative arachnoideum-achillioides hybrid derivatives, compared to var. achillioides, have smaller, broader, thinner, and more shallowly lobed leaves, and shorter pappi. Putative achillioides-grandiflorum hybrid derivatives, compared to var. achillioides, have longer peduncles, larger heads (often borne singly), and longer ray laminae. Variety aphanactis (2n = 32), an Inner Coast Range local, rayless variant, is probably of achillioides-grandiflorum parentage. Varieties achillioides, arachnoideum, grandiflorum, and lanceolatum overlap in northwestern California and southwestern Oregon. L. Constance (1937, p. 89), referring to the Klamath area, observed “that it seems quite impossible to assign many specimens definitely to any one subspecific category.” Variety achillioides passes gradually through northern California and southern Oregon populations into var. leucophyllum west of the Cascade Mountains. Oregon specimens with ternately lobed leaves and larger heads often borne singly (Eriophyllum ternatum Greene) are part of the continuum.

L. Constance (1937, p. 87) had var. achillioides, although “uncommon in the Sierra Nevada, occurring as far south as Mariposa County.”

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Key

1. Ray florets 8–9 (disc corolla tubes glabrous; s California)	var. hallii
1. Ray florets usually (5–)8–15, rarely 0 (disc corolla tubes glandular or glandular-hairy)	→ 2
2. Pappi to 0.2 mm, sometimes coroniform, rarely 0	→ 3
2. Pappi (0.3–)0.5–2 mm	→ 4
3. Proximal leaves pinnately lobed, lobes 3–5, abaxial faces loosely cobwebby-woolly; California, Coast Ranges	var. arachnoideum
3. Proximal leaves coarsely serrate or shallowly lobed distally, abaxial faces densely silky-woolly; California, Sierra Nevada	var. croceum
4. Proximal leaves 1–2(–3)-pinnately lobed	→ 5
4. Proximal leaves laciniately toothed, serrate, or entire	→ 8
5. Proximal leaves 1-pinnately lobed; peduncles mostly 5–30 cm	→ 6
5. Proximal leaves 1–2(–3)-pinnately lobed (sinuses almost to midribs); peduncles mostly 3–15 cm	→ 7
6. Proximal leaves usually lobed (beginning in proximal 1/2 of leaf); peduncles mostly 10–30 cm; California, sw Oregon	var. grandiflorum
6. Proximal leaves usually lobed (beginning in distal 1/2 of leaf); peduncles mostly 5–15(–20) cm; Idaho, Montana, ne Oregon, e Washington	var. lanatum
7. Perennials (often clumped); proximal leaves usually mostly opposite, 1(–2)-pinnately lobed, lobes ± linear (with 0–2 teeth, ultimate margins not crispate), abaxial faces usually densely gray-woolly; heads 2–5 per array or borne singly; ray laminae 8–20 mm; British Columbia, sw Oregon, Washington	var. leucophyllum
7. Perennials (sometimes flowering first year); proximal leaves usually mostly alternate, 1–2(–3)-pinnately lobed, lobes usually ± triangular (with 0–4 teeth, ultimate margins often crispate), abaxial faces woolly; heads usually 3–8 per array; ray laminae usually 6–9(–16) mm; California, Nevada, s Oregon	var. achilleoides
8. Leaves: margins revolute, abaxial faces woolly, adaxial tufted-woolly or glabrate	→ 9
8. Leaves: margins usually plane, sometimes slightly revolute in var. integrifolium, abaxial and adaxial faces woolly	→ 10
9. Peduncles mostly 10–30 cm; cypselae (2.4–)2.5–3.5(–4) mm; California, sw Oregon	var. grandiflorum
9. Peduncles mostly 5–15(–20) cm; cypselae (3.4–)3.5–5 mm; Idaho, Montana, ne Oregon, e Washington	var. lanatum
10. Involucres 6–10 mm diam.; ray florets (5–)8(–10)	var. integrifolium
10. Involucres 10–15 mm diam.; ray florets 10–13(–15)	→ 11
11. Involucres 10–12 mm diam.; ray laminae 6–7 mm; s California	var. obovatum
11. Involucres 12–15 mm diam.; ray laminae 7–10(–15) mm; n California,s Oregon	var. lanceolatum