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

ten-lobed 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, 6–60 cm;

branches ascending to spreading, quadrangular-ridged, wingless distally, glabrous or sparsely 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 to spreading;

blade linear-filiform to linear, (6–)8–25 x 0.4–1.5 mm, margins entire, often siliceous, adaxial surface finely scabrous;

axillary fascicles absent.

Inflorescences

racemes, elongate, flowers 2 per node;

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

racemes, short to elongate, interrupted, flowers 1 or 2 per node;

bracts usually shorter than, sometimes both shorter and longer than, pedicels.

Pedicels

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

ascending to +/- spreading, (3–)6–26 mm, glabrous.

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 obconic to hemispheric, tube (1.3–)2–4.5(–5.5) mm, glabrous, lobes subulate to triangular, (0.2–)0.5–1.5(–2) mm;

corollas pale pink to pink, usually with 2 yellow lines and red spots in abaxial throat, (5–)6–14.5 mm, throat pilose externally and villous within across bases and sinus of adaxial lobes, lobes: abaxial spreading, adaxial erect to recurved, (2–)3–6(–7) mm, glabrous externally;

proximal anthers parallel to filaments, distal perpendicular to filaments, pollen sacs 0.8–2.2 mm;

style exserted, (5–)7–12 mm.

Capsules

globular, 4–7 mm.

ovoid, 3.5–5 mm.

Seeds

tan to brown, 0.5–1.5 mm.

yellowish tan, 0.3–1.2 mm.

2n

= 28.

= 26.

Agalinis tenuifolia

Agalinis decemloba

Phenology Flowering (late Jul–)Aug–Nov. Flowering Aug–mid Oct.
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. Sand plain grasslands, dry prairie remnants, dry roadsides, cemeteries, margins and openings in mesic to dry mixed woodlands, serpentine grasslands.
Elevation 0–1600 m. (0–5200 ft.) 0–700 m. (0–2300 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; CT; DC; KY; MA; MD; NC; NY; PA; RI; SC; TN; VA
[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.)

J. B. Pettengill and M. C. Neel (2011) provided morphological and molecular evidence that showed Agalinis decemloba and A. acuta are conspecific. Their data also indicated that A. tenella is most closely related to A. decemloba (including A. acuta) and may merit infraspecific status within A. decemloba. The authors maintain A. tenella based on morphological characters that include: larger corollas with proportionally larger recurved lobes; larger anthers; longer styles and stigma; and larger plants with many laxly spreading branches than A. decemloba. Agalinis decemloba is rare, and populations show extreme variation in numbers of plants produced per year. The authors agree with Pettengill and Neel that A. decemloba, as circumscribed here to include the federally listed endangered A. acuta, is threatened and deserves protection. Study of a population of A. decemloba (as A. acuta) in Massachusetts showed these plants were self-compatible (Neel 2002). Agalinis decemloba is distinguished from A. obtusifolia by the following characteristics: stems and branches flexible and drying green versus stiff and drying stramineous, leaves linear to linear-filiform versus linear-elliptic to spatulate, bracts shorter than to slightly longer than pedicels versus much shorter than pedicels, calyx lobes subulate to triangular versus deltate, and corollas usually with two yellow lines and red spots in abaxial throat versus two yellow lines and pink spots absent or pale in abaxial throat.

Agalinis decemloba is in the Center for Plant Conservation’s National Collection of Endangered Plants.

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

Source FNA vol. 17, p. 554. FNA vol. 17, p. 540.
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. 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. 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 decemloba, A. acuta, G. acuta
Name authority (Vahl) Rafinesque: New Fl. 2: 64. (1837) (Greene) Pennell: Bull. Torrey Bot. Club 40: 434. (1913)
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