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yellow ray goldfields

goldfields

Habit Annuals, to 60 cm. Annuals (perennials), to 40(–60) cm (taprooted or roots fibrous, fleshy and clustered in Lasthenia californica subsp. bakeri).
Stems

erect, branched distally, glabrous or slightly hairy.

usually erect, sometimes decumbent, prostrate, or sprawling, simple or branched (usually distally, often proximally in decumbent plants).

Leaves

linear or subulate, 40–150 × 2–3+ mm, margins entire, faces glabrous.

mostly cauline; opposite; petiolate or sessile;

blades usually linear, often 1(–2)-pinnately lobed, ultimate margins entire or toothed, faces glabrous or hairy.

Involucres

hemispheric, 5–10 mm.

obconic to hemispheric, 3–5+ mm diam.

Receptacles

± conic, papillate, glabrous or sparsely hairy.

hemispheric to narrowly conic or subulate, smooth, papillate, or pitted, glabrous or hairy, epaleate.

Ray florets

7–15; (corollas yellow) laminae oblong, 4–14 mm.

4–16, pistillate, fertile;

corollas yellow to orangish (sometimes white in L. debilis, often somewhat darker proximally, laminae rarely lacking in L. glaberrima and L. microglossa).

Disc florets

5–100+, bisexual, fertile;

corollas yellow to orangish (sometimes white in L. debilis), tubes shorter than or about equaling funnelform or campanulate throats, lobes (4–)5, deltate.

Phyllaries

10–14, ± lanceolate (distinct tips ± deltate), glabrous but for apices.

usually persistent, sometimes falling with cypselae, 4–18 in 1(–2) series (usually ± erect in fruit, distinct or ± connate, narrowly oblong to broadly ovate, mostly herbaceous, bases flat or weakly cupped, faces not woolly, except sometimes in L. minor and L. platycarpha).

Heads

usually radiate, sometimes ± disciform (in L. glaberrima and L. microglossa), borne singly or in ± corymbiform arrays.

Cypselae

gray, clavate or obovoid, 2–3.5 mm, margins not ciliate, faces glabrous, or hairy and papillate (papillae rusty or yellowish, wartlike);

pappi 0.

(black to gray) usually cylindric to obovoid, glabrous or hairy, sometimes papillate (flattened, margins fringed with blunt, curved hairs in L. chrysantha);

pappi 0, or of 1–12 erose, fimbriate, or laciniate, truncate or aristate scales (sometimes 2 kinds in combination on single cypselae).

Anther

appendages deltate or broadly ovate.

x

= 8.

Lasthenia glabrata

Lasthenia

Distribution
from FNA
CA
[WildflowerSearch map]
[BONAP county map]
from USDA
w North America; nw Mexico; South America (Chile)
[BONAP county map]
Discussion

Subspecies 2 (2 in the flora).

Historically, aboriginal Californians used fruits and leaves of Lasthenia glabrata for food. The subspecies are allopatric and almost identical except for their cypselae.

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

Species 18 (17 in the flora).

Lasthenias occur in a wide variety of habitats; some are particularly conspicuous members of vernal-pool floras. The characteristic rich, golden yellow color of Lasthenia gracilis can be seen to cover thousands of hectares of grasslands and open woodlands in early spring, giving the genus its common name. Relatively few taxa are widely distributed; most have relatively restricted distributions. Some are considered to be of conservation concern.

Lasthenia glaberrima, L. kunthii, L. maritima, and L. microglossa are self-pollinating; the rest are self-incompatible, obligate outcrossers. Lasthenia ornduffii and two subspecies of L. californica are perennial; the rest are spring annuals. It is not uncommon to find two Lasthenia species growing more or less sympatrically (in discrete populations).

Most lasthenias show a wide latitude of morphologic response to environmental conditions. Growth of individual plants of Lasthenia is robust in good conditions; in unfavorable conditions, single stems terminating in relatively small heads with relatively few florets are produced. Other morphologic characters such as the degree of leaf dissection, leaf margin, and pappus elements sometimes are plastic.

Circumscriptions of taxa here are based on R. Ornduff (1966b) with realignments proposed by R. Chan (2000). Sections are characterized by morphology, chromosome numbers, biochemistry, ecology, and molecular data.

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

Key
1. Cypselae glabrous, not papillate
subsp. glabrata
1. Cypselae ± hairy and papillate
subsp. coulteri
1. Phyllaries connate 2/3+ their lengths
→ 2
1. Phyllaries distinct or connate 1/4–1/2 their lengths
→ 3
2. Cypselae epappose
sect. Hologymne
2. Cypselae pappose
sect. Lasthenia
3. Leaves entire or ± toothed (not pinnatifid); corolla floral pigments turning deep red in dilute aqueous alkali
→ 4
3. Leaves (especially midstem) usually 1(–2)-pinnately lobed or -pinnatifid, sometimes entire; corolla floral pigments remaining yellow in dilute aqueous alkali
→ 5
4. Ray laminae 2.5–16 mm; receptacles usually narrowly conic to conic (subulate in L. leptalea, ray laminae 2.5–5 mm)
sect. Amphiachaenia
4. Ray laminae 0–1 mm (and anther appendages eglandular), or 3–5 mm; receptacles subulate
sect. Burrielia
5. Cypselae to 1.5 mm
sect. Ornduffia
5. Cypselae 1.5–3.5 mm
→ 6
6. Cypselae pappose (pappi of 4–6 lanceolate to ovate, aristate scales)
sect. Platycarpha
6. Cypselae epappose or pappose (pappi of 2–12 lanceolate, ovate, subulate, aristate scales, sometimes plus 4–5+ shorter, truncate, fimbriate, or laciniate scales)
sect. Ptilomeris
Source FNA vol. 21, p. 343. FNA vol. 21, p. 336. Authors: Raymund Chan, Robert Ornduff†.
Parent taxa Asteraceae > tribe Heliantheae > subtribe Baeriinae > Lasthenia > sect. Hologymne Asteraceae > tribe Heliantheae > subtribe Baeriinae
Sibling taxa
L. burkei, L. californica, L. chrysantha, L. conjugens, L. coronaria, L. debilis, L. ferrisiae, L. fremontii, L. glaberrima, L. gracilis, L. leptalea, L. maritima, L. microglossa, L. minor, L. ornduffii, L. platycarpha
Subordinate taxa
L. glabrata subsp. coulteri, L. glabrata subsp. glabrata
L. sect. Amphiachaenia, L. sect. Burrielia, L. sect. Hologymne, L. sect. Lasthenia, L. sect. Ornduffia, L. sect. Platycarpha, L. sect. Ptilomeris
Name authority Lindley: Edwards’s Bot. Reg. 21: plate 1780. (1835) Cassini: Opusc. Phytol. 3: 88. (1834)
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