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Thompson's Indian paintbrush, Thompson's owl clover, Thompson's paintbrush

castilleja exserta, escobita, exserted Indian paintbrush, owl's clover, purple owl's-clover, purple painted-cup

Habit Herbs, perennial, 0.8–4 dm; from a woody caudex; with a taproot. Herbs, annual, 0.1–4.5 dm; with fibrous roots.
Stems

few to many, erect or ascending, unbranched or branched, hairs spreading, long, stiff, sometimes soft (especially in higher elevations), eglandular, mixed with shorter stipitate-glandular ones.

solitary, erect to ascending, unbranched or diffusely branched from near base, hairs spreading, medium length and long, stiff, mixed with short stipitate-glandular ones.

Leaves

green to purple or reddish brown, linear to narrowly oblong or linear-lanceolate, 1.4–7.4 cm, not fleshy, margins plane to ± wavy, involute or flat, 3(–7)-lobed, apex acuminate;

lobes spreading-ascending, linear, short to long moving up leaf axis, apex acute or obtuse.

green, sometimes purple to brownish, linear or ovate to orbicular in outline, (0.8–)1–5(–7.7) cm, not fleshy, margins plane, involute, (0–)3–9(–11)-lobed, sometimes with secondary lobing, apex acuminate to rounded or acute;

lobes spreading, filiform or linear to narrowly spatulate, apex acute to acuminate or rounded.

Inflorescences

2.5–14 × 1–4 cm;

bracts greenish to pale yellow or reddish brown throughout, or proximally greenish to dull reddish purple, or ruddy brown, distally greenish to yellow-green or yellow, often aging dull reddish to dull purplish, lanceolate to oblong to ovate, 3–5(–9)-lobed;

lobes spreading to ascending, linear to narrowly lanceolate, long, proximal lobes arising below mid length, apex acute to obtuse.

1.5–20 × 2–4 cm;

bracts proximally greenish, dark purple, brownish purple, or white, distally pink, lavender, magenta, light purple, or white on lobe apices, lanceolate to elliptic or narrowly ovate, (3–)5(–9)-lobed, often with 2–4 secondary lobes;

lobes ascending to spreading, linear to filiform or narrowly spatulate, medium length to long, arising below or above mid length, apex rounded to acute.

Corollas

straight, 18–21 mm;

tube 11–16 mm; subequal to calyx, sometimes beak exserted;

beak adaxially green, 5–7(–8) mm;

abaxial lip white, often proximally reddish, prominent, scarcely expanded, ± cylindric, 2.5–4(–5) mm, 50–70% as long as beak, glabrous or obscurely puberulent;

teeth incurved to erect, white, 2.5 mm.

straight, 12–33 mm;

tube 7–20 mm;

beak slightly exserted, hooked near apex, adaxially pink-purple to magenta, rarely white, 5–13 mm, margins colored as bracts, densely villous-hairy;

abaxial lip proximally pink, purple, or magenta, rarely yellow or white, with maroon or deep purple distal to that and white to yellow or pink distally, often with purple spots, distal pale color often aging deep pink or deep red, strongly inflated, pouches 3, 3–8 mm wide, 3–4 mm deep, 3–9 mm, 67–80% as long as beak;

teeth erect, white, yellow, or purple, often with purple or maroon spots, 0.5–2 mm.

Calyces

colored as bracts, 12–25 mm;

abaxial and adaxial clefts 4–8 mm, 20–60% of calyx length, deeper than laterals, lateral (0–)1–3 mm, 7–25% of calyx length;

lobes linear, lanceolate, or triangular, apex acute, sometimes obtuse.

colored as bracts, 10–26 mm;

abaxial clefts 4–12 mm, adaxial 9–18 mm, abaxial ca. 50% of calyx length, adaxial ca. 67% of calyx length, at least adaxial deeper than others, lateral 2.5–9 mm, 15–45% of calyx length;

lobes linear (to narrowly oblanceolate), apex rounded to acute.

Filaments

with spreading, long, soft hairs.

2n

= 24, 48.

= 24.

Castilleja thompsonii

Castilleja exserta

Phenology Flowering Apr–Aug(–Sep).
Habitat Dry slopes, ridges, scabland lithosol soils, meadows, sagebrush steppes, valleys, montane to alpine.
Elevation 200–2100 m. (700–6900 ft.)
Distribution
from FNA
OR; WA; BC
[WildflowerSearch map]
[BONAP county map]
from FNA
AZ; CA; NM; nw Mexico
[WildflowerSearch map]
[BONAP county map]
Discussion

Castilleja thompsonii is a characteristic species of the sagebrush communities on the eastern slope of the Cascade Range in Washington, and in the high deserts of the Columbia Basin. Historically, its range approached but apparently never entered Idaho in the Spokane River valley, but much of its habitat in that area is now converted to agriculture or suburban development or overwhelmed by non-native, invasive plants. Castilleja thompsonii occurs in a few sites in the Okanogan Valley region of southern British Columbia and at one site on the eastern slopes of the Cascade Range in Wasco County, Oregon. A distinctive form from the subalpine and alpine zones of Mt. Adams, in the southern Cascade Range of Washington, was named C. villicaulis. This form may merit varietal status under C. thompsonii. While both names were described in the same paper, C. thompsonii is the name used in all regional floras since their publication, after C. villicaulis was reduced to synonymy by M. Ownbey (1959).

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

Varieties 3 (3 in the flora).

In addition to the characters in the key, Castilleja exserta is distinguished from the similar C. densiflora by its conspicuously hairy and apically hooked beak. As a result, the capitate stigma is exserted more or less horizontally from the corolla beak. In contrast, C. densiflora has an unhooked, inconspicuously puberulent beak, from which the stigma emerges more vertically. Castilleja exserta hybridizes with C. attenuata in southern California and with C. lineariloba in central California, and it reportedly crosses occasionally with C. densiflora in southern California.

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

Key
1. Abaxial lips of corollas deep red-purple proximally, with distal 1/4 bright yellow to yellow-orange, becoming orange or red after anthesis; w Mojave Desert, California.
var. venusta
1. Abaxial lips of corollas variably colored, proximally pink to deep red-purple or white, with distal 1/4–1/3 white, yellow, or yellow-orange; widespread in Arizona and California, rare in New Mexico or limited to the coastal regions of California.
→ 2
2. Bracts usually less than 5 mm wide, lobes filiform to linear; inland and near-coastal grasslands and meadows; Arizona, w California, sw New Mexico.
var. exserta
2. Bracts 5–7 mm wide, lobes linear to narrowly spatulate; coastal dunes and bluffs; California.
var. latifolia
Source FNA vol. 17, p. 661. FNA vol. 17, p. 606.
Parent taxa Orobanchaceae > Castilleja Orobanchaceae > Castilleja
Sibling taxa
C. affinis, C. ambigua, C. angustifolia, C. applegatei, C. aquariensis, C. arachnoidea, C. attenuata, C. brevilobata, C. brevistyla, C. campestris, C. cervina, C. chambersii, C. chlorotica, C. christii, C. chromosa, C. chrymactis, C. chrysantha, C. cinerea, C. citrina, C. coccinea, C. collegiorum, C. covilleana, C. crista-galli, C. cryptantha, C. cusickii, C. densiflora, C. dissitiflora, C. disticha, C. elata, C. elegans, C. elmeri, C. exserta, C. flava, C. foliolosa, C. fraterna, C. genevieveana, C. glandulifera, C. gleasoni, C. gracillima, C. grisea, C. haydenii, C. hispida, C. hololeuca, C. hyperborea, C. indivisa, C. integra, C. kaibabensis, C. kerryana, C. kraliana, C. lacera, C. lanata, C. lasiorhyncha, C. lassenensis, C. latifolia, C. lemmonii, C. leschkeana, C. levisecta, C. linariifolia, C. lindheimeri, C. lineariloba, C. lineata, C. litoralis, C. lutescens, C. martini, C. mendocinensis, C. mexicana, C. miniata, C. minor, C. mogollonica, C. mollis, C. montigena, C. nana, C. nelsonii, C. nervata, C. nivea, C. occidentalis, C. oresbia, C. organorum, C. ornata, C. pallescens, C. pallida, C. parviflora, C. parvula, C. patriotica, C. peckiana, C. peirsonii, C. pilosa, C. plagiotoma, C. praeterita, C. pruinosa, C. puberula, C. pulchella, C. purpurascens, C. purpurea, C. raupii, C. revealii, C. rhexiifolia, C. rigida, C. rubicundula, C. rubida, C. rupicola, C. salsuginosa, C. scabrida, C. schizotricha, C. septentrionalis, C. sessiliflora, C. subinclusa, C. suksdorfii, C. tenuiflora, C. tenuis, C. tomentosa, C. uliginosa, C. unalaschcensis, C. victoriae, C. viscidula, C. wightii, C. wootonii, C. xanthotricha
C. affinis, C. ambigua, C. angustifolia, C. applegatei, C. aquariensis, C. arachnoidea, C. attenuata, C. brevilobata, C. brevistyla, C. campestris, C. cervina, C. chambersii, C. chlorotica, C. christii, C. chromosa, C. chrymactis, C. chrysantha, C. cinerea, C. citrina, C. coccinea, C. collegiorum, C. covilleana, C. crista-galli, C. cryptantha, C. cusickii, C. densiflora, C. dissitiflora, C. disticha, C. elata, C. elegans, C. elmeri, C. flava, C. foliolosa, C. fraterna, C. genevieveana, C. glandulifera, C. gleasoni, C. gracillima, C. grisea, C. haydenii, C. hispida, C. hololeuca, C. hyperborea, C. indivisa, C. integra, C. kaibabensis, C. kerryana, C. kraliana, C. lacera, C. lanata, C. lasiorhyncha, C. lassenensis, C. latifolia, C. lemmonii, C. leschkeana, C. levisecta, C. linariifolia, C. lindheimeri, C. lineariloba, C. lineata, C. litoralis, C. lutescens, C. martini, C. mendocinensis, C. mexicana, C. miniata, C. minor, C. mogollonica, C. mollis, C. montigena, C. nana, C. nelsonii, C. nervata, C. nivea, C. occidentalis, C. oresbia, C. organorum, C. ornata, C. pallescens, C. pallida, C. parviflora, C. parvula, C. patriotica, C. peckiana, C. peirsonii, C. pilosa, C. plagiotoma, C. praeterita, C. pruinosa, C. puberula, C. pulchella, C. purpurascens, C. purpurea, C. raupii, C. revealii, C. rhexiifolia, C. rigida, C. rubicundula, C. rubida, C. rupicola, C. salsuginosa, C. scabrida, C. schizotricha, C. septentrionalis, C. sessiliflora, C. subinclusa, C. suksdorfii, C. tenuiflora, C. tenuis, C. thompsonii, C. tomentosa, C. uliginosa, C. unalaschcensis, C. victoriae, C. viscidula, C. wightii, C. wootonii, C. xanthotricha
Subordinate taxa
C. exserta var. exserta, C. exserta var. latifolia, C. exserta var. venusta
Synonyms C. villicaulis Orthocarpus exsertus
Name authority Pennell: Proc. Acad. Nat. Sci. Philadelphia 99: 178. (1947) — (as thompsoni) (A. Heller) T. I. Chuang & Heckard: Syst. Bot. 16: 657. (1991)
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