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gérardie à feuilles ténues, slender-leaf agalinis, slender-leaf false foxglove

ridgestem false foxglove

Stems

simple or branched, 10–100 cm;

branches ascending to spreading, quadrangular, sharply ridged to winged distally, glabrate, sometimes scabrous.

simple or branched, 30–90(–110) cm;

branches spreading-ascending, quadrangular, with siliceous ridges on angles, scabridulous.

Leaves

spreading, sometimes arching, ascending, or reflexed;

blade narrowly linear to linear-lanceolate, 10–70 x 0.3–6 mm, not fleshy, margins entire, adaxial surface scabrous;

axillary fascicles absent or shorter than subtending leaves.

ascending;

blade subulate, elliptic, or filiform, (1–)4–13 x 0.3–1.1 mm, margins entire, heavily siliceous, scabridulous, adaxial surface siliceous, scabridulous;

axillary fascicles absent.

Inflorescences

racemes, elongate, flowers 2 per node;

bracts shorter than, or longer than, or both shorter and longer than, pedicels.

racemiform-paniculate, with short multinoded floriferous branches, some with pseudoterminal flowers, flowers 1 or 2 per node;

bracts shorter than or sometimes equal to pedicels.

Pedicels

ascending-spreading, some upcurved distally, 6–25 mm, glabrous.

ascending, 4–16 mm, +/- scabridulous.

Flowers

calyx obconic to hemispheric, tube 2.3–5.5 mm, glabrous, lobes subulate to triangular-subulate, 0.3–2 mm;

corolla pink to rose purple, with 2 yellow lines and red spots in abaxial throat, 7–23 mm, throat pilose externally and glabrous within across bases and sinus of adaxial lobes, lobes: abaxial projected or spreading, adaxial projected over distal anthers, 2–8 mm, abaxial pilose externally, adaxial glabrous externally or pilose proximally;

proximal anthers perpendicular or oblique to filaments, distal perpendicular and vertical to filaments, pollen sacs 1–4 mm;

style exserted, 6.7–18 mm.

calyx campanulate to funnelform, tube 2.5–3.2 mm, glabrous, lobes subulate to triangular-subulate, 0.1–1 mm;

corolla pink to dark pink, with 2 yellow lines and red spots in abaxial throat, 15–25 mm, throat pilose externally and villous within across bases and sinus of adaxial lobes, lobes: abaxial spreading, adaxial reflexed-spreading, 4–7(–9) mm, glabrous externally;

proximal anthers parallel to filaments, distal oblique or perpendicular to filaments, pollen sacs 1.8–2.6 mm;

style exserted, 6–11 mm.

Capsules

globular, 4–7 mm.

globular, 4–6 mm.

Seeds

tan to brown, 0.5–1.5 mm.

tan to yellow, 0.5–0.9 mm.

2n

= 28.

= 26.

Agalinis tenuifolia

Agalinis oligophylla

Phenology Flowering (late Jul–)Aug–Nov. Flowering late Sep–mid Nov.
Habitat Wet to dry roadsides, ditches, margins of streams and ponds, borders of woodlands, dry to moist prairies, fallow fields, railroad embankments, rocky cliff faces and bluffs. Moist to dry longleaf pine savannas, edges of pine plantations, dry roadsides, chalky outcrops, seepage slopes of clay roadsides.
Elevation 0–1600 m. (0–5200 ft.) 0–300 m. (0–1000 ft.)
Distribution
from FNA
AL; AR; CO; CT; DC; DE; FL; GA; IA; IL; IN; KS; LA; MA; MD; ME; MI; MO; MS; NC; ND; NE; NH; NJ; NM; NY; OH; OK; PA; RI; SC; SD; TN; TX; VA; VT; WI; WV; WY; MB; NB; NS; ON; PE; QC
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; AR; LA; MS; TN; TX
[BONAP county map]
Discussion

Populations of Agalinis tenuifolia in New Brunswick, Nova Scotia, and possibly Prince Edward Island in Canada are presumed introduced.

Agalinis tenuifolia is the most widespread and morphologically variable species of the genus in the flora area. Infraspecific taxa have been recognized based on differences in sizes of corollas, calyx lobes, anthers, capsules, and leaves; presence or absence of axillary fascicles; density of indument on stamens; branches ascending versus spreading; and even the stoutness of reticulations on seed coats. These characters intergrade within and among populations and occur in many other combinations in addition to those described, making these infraspecific taxa arbitrary and inconsistent with plants in the field. Pressed specimens of A. tenuifolia are often confused with A. gattingeri from which they differ by lacking a villous band of trichomes within the corolla at the bases of the adaxial corolla lobes present in A. gattingeri; projecting adaxial corolla lobes versus erect to recurved lobes in A. gattingeri; elongate racemes with two flowers per node versus one flower per node, often appearing to terminate branches in A. gattingeri; and low wings of tissue on the branch angles that are absent or less pronounced in A. gattingeri.

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

Plants of Agalinis oligophylla are rare in the easternmost portions of the range; they are abundant farther west into Texas. Agalinis oligophylla is often the last species of Agalinis to begin flowering, usually in late September, sometimes not until mid October and often remains in flower well into November. Unbranched plants of A. oligophylla can be confused with A. aphylla, with which it often shares the habitat. Agalinis oligophylla can be distinguished from A. aphylla by the longer leaves, more diffusely branched inflorescence, glabrous style, and the much later flowering period of A. oligophylla. Also, on the older buds of A. oligophylla the corolla is globular, but in A. aphylla the corolla on older buds is obovoid. Corollas of A. oligophylla are asymmetric; the adaxial side of the corolla throat is conspicuously shorter than the upcurved abaxial side of the corolla. The buds, pedicels, and capsules of A. oligophylla turn dark brown or blackish, and corollas turn dark purplish or pinkish brown when dried. These dark structures contrast strikingly with the pale green to gray (or reddish) branches and leaves.

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

Source FNA vol. 17, p. 554. FNA vol. 17, p. 549.
Parent taxa Orobanchaceae > Agalinis Orobanchaceae > Agalinis
Sibling taxa
A. aphylla, A. aspera, A. auriculata, A. caddoensis, A. calycina, A. decemloba, A. densiflora, A. divaricata, A. edwardsiana, A. fasciculata, A. filicaulis, A. filifolia, A. flexicaulis, A. gattingeri, A. georgiana, A. harperi, A. heterophylla, A. homalantha, A. laxa, A. linifolia, A. maritima, A. navasotensis, A. neoscotica, A. obtusifolia, A. oligophylla, A. plukenetii, A. pulchella, A. purpurea, A. setacea, A. skinneriana, A. strictifolia, A. tenella, A. viridis
A. aphylla, A. aspera, A. auriculata, A. caddoensis, A. calycina, A. decemloba, A. densiflora, A. divaricata, A. edwardsiana, A. fasciculata, A. filicaulis, A. filifolia, A. flexicaulis, A. gattingeri, A. georgiana, A. harperi, A. heterophylla, A. homalantha, A. laxa, A. linifolia, A. maritima, A. navasotensis, A. neoscotica, A. obtusifolia, A. plukenetii, A. pulchella, A. purpurea, A. setacea, A. skinneriana, A. strictifolia, A. tenella, A. tenuifolia, A. viridis
Synonyms Gerardia tenuifolia, A. besseyana, A. tenuifolia var. leucanthera, A. tenuifolia var. macrophylla, A. tenuifolia var. parviflora, A. tenuifolia var. polyphylla, G. besseyana, G. tenuifolia subsp. leucanthera, G. tenuifolia subsp. macrophylla, G. tenuifolia subsp. parviflora, G. tenuifolia subsp. polyphylla Gerardia aphylla var. grandiflora, G. microphylla
Name authority (Vahl) Rafinesque: New Fl. 2: 64. (1837) Pennell: Bull. Torrey Bot. Club 40: 432. (1913)
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