Herbs, annuals. Stems erect to ascending or decumbent, glabrous or hairy, often glandular. Leaves cauline, opposite; petiole present on proximals, absent on distals; blade not fleshy (fleshy in C. callosa), not leathery, margins entire, sometimes toothed. Inflorescences terminal, interrupted whorls or flowers solitary; bracts present. Pedicels present; bracteoles present, distalmost sometimes absent. Flowers bisexual; sepals 5, connate, caly× bilaterally symmetric, urceolate or cup-shaped to campanulate, lobes deltate to ovate, inner face glabrous or white-hairy (C. antonina); corolla white, pink, purple, or blue with markings on adaxial lobes, bilaterally symmetric, bilabiate, tubular to funnelform, tube base not spurred abaxially, ± saccate or gibbous (forming a prominent or obscure pouch) adaxially, lobes 5, abaxial 3, 2 as wings, middle lobe of abaxial lip (keel) folded lengthwise, enclosing stamens and styles, adaxial 2, distal portion spreading to reflexed (banner); stamens 4, adnate near base of throat, didynamous, included, filaments glabrous or hairy, spur 0 or 1; staminode 1, glandlike; ovary 2-loculed, placentation axile; stigma minutely 2-lobed. Fruits capsules, dehiscence septicidal and loculicidal. Seeds 2–16, reddish brown, brown, or cinnamon red, oblong, ellipsoid, ovoid, or globular, rarely prismatic or hourglass-shaped, margins thickened and inrolled proximally, or thin and not inrolled, hollow near attachment to placenta, wings absent, rarely present. x = 7.
North America, nw Mexico.
Species 21 (21 in the flora).
The flowers in Collinsia resemble those of Fabaceae subfam. Faboideae. The two lobes of the adaxial corolla lip are partially connate and distally reflexed; these lobes, the banner, often contain taxon-specific markings. The three lobes of the abaxial lip are more complexly connate: the two lateral lobes are referred to as wings; the central lobe, the keel, is folded, curved along its distal portion, and concealed by the wings. The keel encloses the stamens, style, and stigma.
In species with purple or blue corollas, some plants produce white or pink corollas. The frequency of such plants is usually very low in most species. The frequency of such plants in Collinsia heterophylla is much higher in the South Coast Ranges of California, and this trait appears to have reached fixation in some populations.
In taxa that are conspicuously glandular, a reaction occurs when the glands are ruptured, either when handled roughly in the field or when pressed for preservation as a specimen. The ruptured glands will cause a stain that is initially iron yellow-orange and later becomes purplish.
|1||Corollas ± uniformly dark purple, rarely pale pinkish purple, banner lobe bases with 2-crested, crescent-shaped folds extending 1–1.5 mm from throat openings.||Collinsia greenei|
|1||Corollas uniformly pale, or with pale regions, especially on throats and bases of banners, banner lobe bases with folds not 2-crested, not crescent-shaped, extending less than 1 mm from throat openings, or folds absent.||> 2|
|2||Flowers crowded; pedicels shorter than calyces, not or scarcely visible.||> 3|
|3||Stamens: basal spurs of adaxial filaments 1.||Collinsia heterophylla|
|3||Stamens: basal spurs of adaxial filaments 0 or 1.||> 4|
|4||Banner lengths 0.7–0.9+ times wings.||> 5|
|5||Corollas ± uniformly whitish to pinkish, banner lobes toothed; leaf blade margins crenate.||Collinsia bartsiifolia|
|5||Corollas tinged bluish, distally violet to magenta, banner purple-dotted near base, banner lobes notched; leaf blade margins entire, rarely serrate.||Collinsia concolor|
|4||Banner lengths less than 0.8 times wings.||> 6|
|6||Banner lengths 0.5–0.8 times wings.||Collinsia bartsiifolia|
|6||Banner lengths 0.1–0.5 times wings.||> 7|
|7||Leaf blade abaxial surfaces glabrous; inflorescences: flower whorls 1 per branch; banner reflexed portion 1 mm, shorter than basal portion, brownish, not red-banded; wings sparsely and finely glandular, not hairy; sand dunes.||Collinsia corymbosa|
|7||Leaf blade abaxial surfaces densely hairy; inflorescences: flower whorls 2–8 on main axes, fewer on lateral branches; banner reflexed portion 2–3.5 mm, equal to basal portion, red-banded; wings usually hairy adaxially; rocky habitats.||Collinsia tinctoria|
|2||Flowers not crowded proximally; pedicels longer than calyces, visible, distalmost sometimes not or scarcely visible (C. multicolor).||> 8|
|8||Caly× lobes: inner face white-hairy; siliceous shale screes.||Collinsia antonina|
|8||Caly× lobes: inner face glabrous; rocky, gravelly, sandy, or loamy soils, rarely on siliceous shale screes.||> 9|
|9||Caly× lobe apices acute to acuminate.||> 10|
|10||Stamens: adaxial filaments glabrous; caly× lobes equal to capsules.||> 11|
|11||Corollas 8–15 mm, wings 2–6 mm wide, widely obovate, throats strongly angled to tubes.||Collinsia grandiflora|
|11||Corollas 4–8 mm, wings 1(–3) mm wide, oblong, throats barely angled to tubes.||Collinsia parviflora|
|10||Stamens: adaxial filaments hairy; caly× lobes surpassing capsules.||> 12|
|12||Keels sparsely long-hairy near tips; capsules with red blotches; seeds round, margins thin, not inrolled.||Collinsia sparsiflora|
|12||Keels glabrous or sparsely glandular; capsules without red blotches; seeds oblong to oval, margins thickened, inrolled.||> 13|
|13||Banner bases white, with maroon dots and lines, rarely unmarked.||Collinsia multicolor|
|13||Banner bases yellow, with maroon or orange spots.||> 14|
|14||Pedicels glandular abaxially, glabrate adaxially; corolla wings and keels bluish, wings notched less than 0.1 times whole lengths, banner lengths (0.7–)0.8–1 times wings, bases with maroon spots; seeds 2–4, 2–3 mm.||Collinsia verna|
|14||Pedicels glandular abaxially and adaxially; corolla wings and keels violet, wings notched 0.2 times whole lengths, banner lengths 0.6–0.7(–0.8) times wings, bases with orange spots; seeds 6–12, 1–1.5 mm.||Collinsia violacea|
|9||Caly× lobe apices subacute, obtuse, or rounded.||> 15|
|15||Inflorescences ± eglandular.||Collinsia parryi|
|15||Inflorescences conspicuously glandular.||> 16|
|16||Pedicels pendent and/or sigmoid in fruit, sometimes reflexed; distalmost bracts 0–2 mm.||> 17|
|17||Wings surpassing keel by 1–2 mm.||Collinsia wrightii|
|17||Wings equal to keel.||> 18|
|18||Leaf blades linear, lengths usually 6+ times widths.||Collinsia torreyi|
|18||Leaf blades elliptic to ovate, lengths usually 2–5 times widths.||Collinsia latifolia|
|16||Pedicels spreading to ascending; distalmost bracts 2+ mm.||> 19|
|19||Leaf blades oblong to ovate, lanceolate, or oblanceolate, lengths usually less than 6 times widths.||> 20|
|20||Annuals fleshy; distal leaf blade bases clasping; seeds 6–8; calyces campanulate to urceolate, lobes equal to capsules.||Collinsia callosa|
|20||Annuals not fleshy; distal leaf blade bases tapered; seeds 2; calyces campanulate, lobes surpassing capsules.||Collinsia childii|
|19||Leaf blades linear to narrowly oblanceolate, lengths usually 6+ times widths.||> 21|
|21||Corollas 8–12(–15) mm, pouches prominent, throats strongly angled to tubes, banner reflexed portion lengths 1.5–2 times throats; seeds round to oblong, margins thin, scarcely inrolled.||Collinsia linearis|
|21||Corollas 4–8 mm, pouches ± hidden by calyces, throats barely angled to tubes, banner reflexed portion lengths 1 times throats; seeds oblong to ovate, margins thickened, inrolled.||Collinsia rattanii|