Species: Nuttallanthus texanus (Scheele) D.A. Sutton

comments | credits | copyright

Back to: Plants at Risk in Saskatchewan

Nuttallanthus texanus (Scheele) D.A. Sutton

Species Image Gallery
(opens in a new window)

TAXONOMY

Family:

Scrophulariaceae

Genus:

Nuttallanthus

Species Synonyms:

Linaria canadensis var. texana (Scheele) Pennell
Linaria texana Scheele

Common Names:

Texas toadflax
field toadflax

DISTRIBUTION

Canada:

southwestern British Columbia, west-central Saskatchewan

Saskatchewan:

west-central Saskatchewan; Alsask

Ecoregion:

Moist Mixed Grassland

HABITAT

Saskatchewan:

dry, open areas

Canada:

dry sandy or sterile soil

RARITY STATUS

Provincial Status According
to Harms (2003):

Endangered

Nature Conservancy Status:

G4 N2

Saskatchewan Species at
Risk Status:

None

COSEWIC Status:

None

Nuttallanthus texanus is endangered because it is extremely rare and has only been found in one location in Saskatchewan. Immediate or probable threats have been identified.

SPECIES DESCRIPTION

Height:

10 – 60 cm

Stems:

annual, 1 – several, erect or ascending, simple or branched above, slender, glabrous, occasionally glandular-pubescent in the inflorescence, with several sterile shoots spreading from base

Leaves:

basal (or at least at the base of the stem) and cauline; basal leaves opposite, 0.5 – 1 cm long, 2 – 3.5 mm wide, oblanceolate to spatulate; cauline leaves alternate, linear, 1 – 2.5 cm long, 1 – 2 mm wide

Inflorescence:

solitary in leaf axils; pedicels 1 – 7 mm long

Flowers:

showy, zygomorphic; calyx 3 – 3.5 mm long, segments broadly lanceolate; corolla 10 – 13 mm long, spur filiform curved, 6 – 11 mm long, upper lip 3.5 – 5 mm long, lobes erect, lower lip 7 – 11 mm long, lobes round and spreading, pale blue or purple; stamens 4, didynamous; stigma capitate

Fruits:

capsule subglobose; seeds truncate, densely tuberculate

SCROPHULARIACEAE KEY FOR GENERA FOUND IN SASKATCHEWAN

1 Stamens 2	2
1 Stamens 4 or 5	4

2 Leaves alternate or all basal; corolla absent	Besseya
2 Leaves opposite; corolla present	3

3 Calyx 4-lobed; stamens exserted	Veronica
3 Calyx 5-lobed; stamens inserted	Gratiola

4 Leaves all basal	5
4 At least some leaves cauline	6

5 Flowers solitary; corolla rotate to campanulate; leaves usually entire or toothed	Limosella
5 Flowers in spicate racemes; corolla bilabiate; leaves pinnately lobed or cleft	Pedicularis

6 Corolla spurred	7
6 Corolla not spurred	9

7 Corolla bluish-purple, 4.5 – 6 mm long, excluding spur; flowers solitary in leaf axils	Chaenorrhinum
7 Corolla yellow or blue, 10 – 13 mm long, excluding spur; flowers in terminal racemes	8

8 Slender annual, 10 – 40 cm tall; corolla blue	Nuttallanthus
8 Stout perennial, 30 – 100 cm tall; corolla yellow and orange	Linaria

9 Floral bracts coloured, concealing flowers	Castilleja
9 Floral bracts green, flowers evident	10

10 Cauline leaves alternate	11
10 Cauline leaves opposite	13

11 Stamens 5, filaments villous; corolla actinomorphic, distinctly 5-lobed	Verbascum
11 Stamens 4, filaments glabrous; corolla zygomorphic, indistinctly 5-lobed	12

12 Basal leaves absent; cauline leaves usually entire, linear; flowers yellow; stamens not enclosed by galea	Orthocarpus
12 Basal leaves commonly present; cauline leaves toothed or pinnately lobed; flowers yellow to white or purple; stamens enclosed by galea	Pedicularis

13 Calyx 4-lobed	14
13 Calyx 5-lobed	17

14 Corolla pink or purple	Odontites
14 Corolla white to yellow	15

15 Calyx about 1 cm long in flower, enlarged, veiny, and membranous in fruit	Rhinanthus
15 Calyx less than 1 cm long in flower, not enlarged in fruit	16

16 Leaves 2 – 10 mm long, lobed, upper leaves sessile	Euphrasia
16 Leaves 10 – 40 mm long, more or less entire, upper leaves petiolate	Melampyrum

17 Staminode present, filamentous	Penstemon
17 Staminode absent or scale-like	18

18 Flowers blue; stamens enclosed by lower lip; upper cauline leaves whorled	Collinsia
18 Flowers greenish to yellow or reddish; stamens not enclosed by lower lip; cauline leaves all opposite	19

19 Corolla green with reddish or purple tinge; flowers less conspicuous, less than 1 cm long; calyx segments deeply parted	Scrophularia
19 Corolla yellow or pinkish red; flowers large and showy, 1 – 4 cm long; calyx segments united into tube	Mimulus