Loeselia spectabilis

Loeselia spectabilis J.M. Porter & V.W. Steinm.—TYPE: MEXICO. Michoacán: municipio de La Huacana, Sierra Las Cruces, 6.5 km (by air) SW of Los Ranchos, Cañada Las Cruces, 18°39’59”N, 102°03’46”W, ca. 650 m, tropical deciduous forest, 15 Mar 2003, V.W. Steinmann 3190 (holotype: RSA; isotypes: IEB, MEXU).

      Suffrutescent perennial; stems slender, branched at base, erect and openly spreading, 1.0–2.5 m long, young branches green, becoming whitish or gray, glandular-pilose with glandular hairs 0.3–0.8 mm long, trichomes often deciduous in age.  Leaves opposite, stiffly spreading to deflexed; cauline leaves shortly petiolate, blades lance-oblong to lanceolate, 30–48 mm long, 10–20 mm broad, broadest toward the proximal end, distal end attenuate, tip subulate, bright green, margin finely serrate toothed, spinulose tipped, finely glandular-puberulent on both surfaces, larger leaves not persistent on flowering branches; upper cauline leaves reduced in size and slightly if at all crowded distally on flowering branches, linear-lanceolate to lanceolate, 15–32 mm long, 1.5–12.0 mm broad, acuminate at apex, tip cuspidate, serrulate with 9–18  teeth, bearing short, aristate setae, along each edge; glandular puberulent.  Inflorescences paniculate, reduced cymes terminating primary and lateral branches, with 1 flower subtended by (3–)4–5  bracts, borne on few-leafed branches 24–53(–65) mm long.  Bracts linear-lanceolate, 8–12 mm long and 1.5–2.8 mm broad, denticulate and with marginal, aristate setae to 0.2 mm long, the outermost bracts chlorophyllous to chartaceous, greenish to white; inner bracts more or less white-hyaline throughout; proximal margins white to hyaline for 0.5–1.0 mm.  Calyx 3.0–3.6 mm long, hyaline along the margins of each lobe and slightly so in the sinuses, lobes 1.1–1.5 mm long, 0.7–0.9 mm broad, entire, triangular acute, with a terminal aristae, calyx tube 2.0–2.3 mm long, 1.5–1.9(–2.3) mm in diameter, glabrous.  Corolla strongly bilaterally symmetrical, 20–25 mm long, the lobes lanceolate to narrowly oblong, apex obtuse, 12–15 mm long, 2.5–4.5 mm broad, entire to denticulate, glandular-ciliate along the margin, villous on abaxial surface, glabrous on adaxial surface, very pale violet, the claw purplish; tube narrow, 7.5–9.0 mm long, glandular-pilose abaxially, nearly the entire length, glabrous adaxially; four filaments declinate, one erect, free from tube 7–8 mm above the base of tube, equally inserted at the sinuses of the corolla lobes, the free portion 8–11 mm long, glabrous; anther 1.5–1.7 mm long, 0.4–0.8 mm broad, pollen white. Pollen grains 45–51 µ in diameter, spheroidal; apertures pantoporate, with 22–28 pores, 2.8-5.3 µ in diameter, circular or slightly oval, often irregular, operculate, the operculum bearing 3–6 spinule like processes; exine c. 2.4 µ thick; sexine c. 1.0 µ thick, pertectate; tectum c. 0.5 thick, suprastriate, punctate, with irregularly distributed spinule-like processes, standing 0.2–0.4 µ tall and 0.2–3.9 µ apart; punctae less than 0.5 ?µ  in diameter, few and irregularly spaced; bacula supporting tectum densely spaced, standing c. 0.5 µ apart, c. 0.8 µ  tall, 0.3–0.5  µ thick; nexine c. 1.0 ?µ thick, thickest at the pore margins, to 2.4. Ovary pyriform, 1.2–1.5 mm tall, ca. 0.6 mm at widest point, ca. 0.5 mm at 1/2 height, glabrous throughout, 1 ovule per carpel; style 21–30 mm long, stigma lobes 0.1–0.3 mm long.  Nectary gland an undulate disk at the base of the ovary, c. 0.4 mm in diameter, c. 0.3 mm high, and c. 0.25 mm deep, bright green.  Fruit 7.0–8.5 mm long, 1.5–2.7 mm wide.  Seeds 1 per locule, 6.5–8.0 mm long, narrowly ovate to narrowly lanceolate in outline, about 5 times as long as wide, somewhat flattened in cross-section; embryo elongate, the cotyledons elongate, longer than the radical and root.

            Loeselia spectabilis has been collected on steep slopes of partially shaded ravines and canyons and on steep rocky slopes in full sun.  It is associated with tropical deciduous forest communities, associated with Albezia occidentalis, Heliotropium rufiphyllum, Ceseria corymbosum, Cocolospermum, Lygastia, Ficus, Randia, Dioscoria, Pisonia, Bursera, Acacia, Celtis, Combretum, Physodium, and Tillandsia, at elevations of 640–700 m, in the Infiernillo region of the Balsas Depression.  Flowering occurs from January to March, and fruiting is most common from late February through May.  The specific epithet, spectabilis, refers to the truly spectacular floral display of this large-flowered Loeselia.


Loeselia spectabilis: Flower of Loeselia spectabilis; scale = 2 mm.

Suffrutescent: Habit and inflorescence architecture of Loeselia spectabilis; scale = 1 cm.

Leaves:Leaf clearings of Loeselia spectabilis, illustrating leaf shape and petiole; scale = 5 mm.

blades: Leaf clearings of Loeselia spectabilis, illustrating venation, margin and teeth morphology; scale = 1 mm.

Inflorescences: Flower of Loeselia spectabilis; scale = 2 mm.

Calyx: Calyx (above) and fruit (below) of Loeselia spectabilis, note the short awn-like apex of the calyx lobes; scale = 2 mm.

Corolla: Flower of Loeselia spectabilis; scale = 2 mm.

glandular-ciliate: Margin of the corrola lobe of Loeselia spectabilis, illustrating the long, glandular trichomes; scale = 1 mm.

Pollen: SEM micrograph of pollen of Loeselia spectabilis; upper panel shows the entire pollen grain; lower panel is a close-up showing the aperture, exine micro-striae, and spinule processes; scale is provided for each panel.

Ovary: Micrograph of the dissected ovary of Loeselia spectabilis; scale = 0.5 mm.

Fruit: Calyx (above) and fruit (below) of Loeselia spectabilis, note the dehiscence pattern of fruit, which extends only about half the length of the capsule; scale = 2 mm.

Seeds: Micrographs of the seed of Loeselia spectabilis; upper left: micrograph if seed, note the embryo shape; upper right: SEM micrograph of whole seed, note the funicular scar (hylem) on the lower seed; lower: close-up SEM images of the seed coat, showing the microsculpture of the testa; scale indicated on the images.

cotyledons: Germinating seedling of Loeselia spectabilis, note the lanceolate cotyledons; scale = 5 mm.

Infiernillo region: (KML file)




Loeselia tancitaroensis

Loeselia tancitaroensis J.M. Porter & V.W. Steinm.—TYPE: MEXICO. Michoacán: municipio de Tancítaro, foothills of Cerro Tancítaro, 1.5 km E of Tancítaro along the road to Zirimóndiro, 19º20’31”N, 102º21’10”W, clay soil, secondary scrub derived from pine-oak forest, 18 Mar 2004, J.M. Porter & V.W. Steinmann 14012 (holotype: RSA; isotypes: IEB, MEXU, SJNM, BRY).

          Herbaceous perennials from a slender, branching taproot; stems slender, 42–150 cm tall, 0.9–2.2 mm in diameter, unbranched or branched at base, erect and openly spreading, young branches green or suffused with purple, glandular-pilose with trichomes 0.2–1.2 mm long, with 5–21 stalk cells, terminating in a 1- to 4-celled, bulbous to truncate gland, trichomes often deciduous.  Lateral branches 8–34 cm long, opposite on the proximal primary stem, alternate distally.  Leaves opposite to sub-opposite, rarely whorled, sometimes becoming alternate distally, stiffly spreading to deflexed; cauline leaves shortly petiolate, the petioles 1–7 mm long, blades ovate to lanceolate, 21–60 mm long, 9–25 mm broad, acute, green, sometimes anthocyanic, the blade somewhat decurrent along the petiole, margin serrate with 5–22 teeth per side, larger leaves not persistent on flowering branches, glandular villous, trichomes much like those of the stem, 0.1–1.0 mm long, with 3–17 stalk cells, terminating in a 1- to 4-celled, bulbous to truncate gland; upper cauline leaves reduced in size distally and on flowering branches, 4–15 mm long, 1.5–7 mm broad, acuminate at base and apex, tip cuspidate, serrulate with 1–8  coarse teeth, bearing short, aristate setae, 0.2–0.5 mm long, glandular-pilose, trichomes like those of the lower leaves.  Inflorescences terminating primary and lateral branches, the branches 7–100 mm long, with 1 flower per bracteate inflorescence unit.  Bracts linear-lanceolate, 2.5–7 mm long, 0.5–1 mm broad, entire, rarely with 1 lateral lobe, terminal aristate setae to 0.5 mm long, outermost bracts herbaceous, innermost bracts white-hyaline from the margin to the central vein of the proximal 1/4 to 1/3, green and herbaceous at the distal tip, glandular puburulent, trichomes 0.07–0.5 mm long, with 2–10 stalk cells, terminating in a 1- to 4-celled, bulbous to truncate gland.  Calyx 3.5–4.5 mm long, hyaline except for the central vascular strands of each lobe and the distal lobes; lobes 2–3.5 mm long, entire, attenuate, with a terminal aristate setae 0.2–0.6 mm long, glandular-pilose throughout, trichomes 0.07–0.45 mm long, with 2–8 stalk cells, terminating in a 1- to 2-celled, bulbous gland.  Corolla bilaterally symmetrical, 9–14.6 mm long, with unequal sinuses, two short lobes and three long lobes, the lobes ovate to narrowly oblong, 4–8 mm long, 1.6–3.0 mm broad, rounded at the apex, glabrous internally, sparsely to moderately glandular-pilose externally, the trichomes 0.09–0.35 mm long, with 3–8 stalk cells, terminating in a single-celled, bulbous gland, trichomes more abundant on the vasculature and distal margin, blue-lavender, pink or rose, usually with purple flecking near the orifice of the corolla throat; tube 1.8–2.2 mm long, glabrous on both adaxial and abaxial surfaces, rarely with 1 or 2 trichomes; throat 2.2–4.8(–5.2) mm long, slightly conic, adaxially glabrous, glandular puburulent on the distal half  of the abaxial throat; filaments straight or slightly declinate, insertion equal, the free portion 6.9–11.7 mm long, glabrous; anthers 1.0–1.8 mm long, 0.4–0.7 mm wide, pollen pale blue. Pollen grains blue, 36–48 µ in diameter, spheroida; apertures pantoporate, with 22–30 pores (Fig. 2b), 3.2-4.8 µ in diameter, circular or slightly oval, often irregular, operculate, the operculum bearing 0–4 spinule like processes; exine c. 2.7 µ thick; sexine c. 1.3  thick, pertectate; tectum ca. 0.5 µ thick, suprastriate, punctate, with irregularly distributed spinule-like processes, standing 0.4–0.6 µ tall and 0.1–5.4 µ apart; punctae less than 0.5 µ in diameter, very sparsely and irregularly spaced, sometimes absent; bacula supporting tectum densely spaced, standing 0.2-0.7 µ apart, c. 0.8 µ tall, 0.4–0.5 µ thick; nexine c. 1.0 µ thick, thickest at the pore margins, to 1.4 µ. Ovary 1.0–1.5 mm long, densely glandular on the distal 1/3 to 3/4, the trichomes 0.06–0.11 mm long, with 3–5 stalk cells, terminating in a single-celled, bulbous gland; 2 ovules per carpel; style 6.6–15 mm long, filiform, stigma lobes 0.5–0.7 mm long.  Fruit ovoid, 2.2–2.7 mm long, 1.5–1.8 mm diameter; seeds 1 or 2 per locule, 1.2–2.3 mm long, 0.9–1.8 mm wide, reddish brown, ellipsoid, rarely somewhat angled, more or less flattened and lenticular, with a very narrow wing or lacking a wing entirely, funicular scar centrally located, linear, short; embryo spatulate, the cotyledons broader than the radicle and root.

            Loeselia tancitaroensis has been collected along roadsides, in ravines and canyons, on slopes, in disturbed soils and along irrigation canals.  It is associated with moist forests, dominated by pine (Pinus pseudostrobus) and oak (Qurecus spp.), at elevations of 1720–2250 m.  Flowering occurs from January to March, rarely through April, and fruiting is most common from March to early May.  The specific epithet acknowledges the mountain range, Cerro Tancitaro, on whose foothills this species is restricted.


Loeselia tancitaroensis: Inflorescence and flowers of Loeselia tancitaroensis, scale = 5 mm

Herbaceous perennials: Loeselia tancitaroensis habit, scale = 1 cm.

trichomes: Microghaph showing glandular trichomes of the stem of Loeselia tancitaroensis, note the uni- to multicellular terminal gland; scale = 0.5 mm.

Leaves: Heteroblastic series of Loeselia tancitaroensis leaves First developed leaves (lowest) are denotes A, more distal nodes have subsequent letters. The letter L represents the terminal portion of the stem, where leaves become sub-oposite; scale = 1 cm. 

margin Photo1; Photo 2: Leaf clearings of Loeselia tancitaroensis showing details of venation, margin, and teeth; scale is indicated in each image.

Calyx: Calyx of of Loeselia tancitaroensis; scale = 1 mm.

Corolla:  Flower of Loeselia tancitaroensis, scale = 5 mm

Pollen: SEMs of Loeselia tancitaroensis pollen. Upper panel: pantoporate pollen grain; center panel: close-up of aperture; lower panel: exine surface shoeing micro-striae, spinule processes, and punctae; scale is indicated in each panel.

Ovary: Dissected ovary of Loeselia tancitaroensis, showing glandular trichomes; scale = 0.25 mm.

seeds Photo1; Photo2:  Light micrograph of Loeselia tancitaroensis seeds, scale = 1 mm (tancitSEED1.jpg). SEM micrograph of Loeselia tancitaroensis seeds showing entire seed as well as derails of seed surface micromorphology; scale is indicated on each panel (tancitSEED4.jpg).

cotyledons Photo1; Photo2: Germinating seedlings of Loeselia tancitaroensis, showing the ovate cotyledons; scale = 5 mm.

collection locations (KML file)


Loeselia Clade Research

Loeselia clade is an obscure and little studied lineage in the flowering plant family Polemoniaceae, which includes Loeselia L., Dayia J.M. Porter, and several species previously included in other genera. In spite of the absence of broad comparative studies, Loeselia has played a pivotal role in hypotheses concerning the origin of temperate members of Polemoniaceae. I have developed a research program to better understand the Loeselia clade (with approximately 22 species). Preliminary studies provide evidence that this group is monophyletic. I am currently seeking funding from the National Science Foundation (REVSYS: Relationships, Diversification, and Monographic study of the Poorly-known Loeselia Clade (Polemoniaceae). to support the completion of this research. Exhaustive taxon sampling within the Loeselia clade and dense sampling of related groups will be used to develop a phylogenetic hypothesis of relationships, based upon chloroplast and nuclear DNA sequence, macromorphological, and micromorphological data. This phylogenetic hypothesis will guide taxonomic revisions for this much-neglected lineage at the generic level and comprehensive monographs of Loeselia and Dayia at all levels. My study is both hypothesis-driven and comparative in nature, with multiple, clear objectives. These include testing taxonomic hypotheses, characterizing changes from outcrossing to self-pollination  in self-incompatible (a self-recognition system that promotes outcrossing) and self-compatible lineages, and it correlation with variation in floral morphology. My approach will be to use data gathered from herbarium visits and loans to inform a carefully planned series of field trips that will be undertaken to obtain material of little known and poorly collected taxa in southern Mexico, Central and northern South America. Preliminary studies indicate that the targeted genic regions, morphological characters, and analyses to be used will permit me to achieve my goals and objectives.


Dayia is a recently described genus of Polemoniaceae. Based on the circumscription of Porter & Johnson (2000) Dayia is restricted to northern Baja California Sur, Mexico, on both the Pacific and Gulf of California coastal regions. Porter and Johnson included two species, Gilia scabra Brandegee, and a newly described one, D. grantii. Below, I provide a description of the genus, as well as a key to distinguish the two species.

DAYIA J.M. Porter, Aliso 19: 71. 2000.

Erect, glandular, largely herbaceous perennials with woody base, or more frequently sub-shrubs. Leaves alternate to less often sub-opposite, pinnatifid to nearly palmate. Inflorescence densely glandular puberulent, composed of reduced (1-) 2-flowered cymes, forming a thyrsoid inflorescence. Corolla glabrous, funnelform to salverform, 14.0–22.0 mm long, pale to deep blue, with a distinct yellow or pale white center. Stamens subequally inserted on the corolla tube and included or equally inserted near the sinuses of the corolla lobes, declinate and exserted; pollen 5–7 zonocolporate with striatoreticulate exine. Fruit a tan to golden brown capsule; seeds 12–46 per cell, minute, ca. 1.2 mm long, the outer testa producing copious fibrils when wetted; embryo achlorophyllous. 2n= 18. Five species. Type: Dayia scabra (Brandegee) J. M. Porter. 

The generic name Dayia, honors Alva G. Day, botanist and student of Polemoniaceae.

Dayia is similar in general appearance to both Ipomopsis and Giliastrum; however, morphological data, as well chromosome number, provide evidence that it is isolated from these genera. The haploid chromosome counts (from dividing pollen mother cells) of D. scabra and D. grantii are n= 9. This contrasts with all known members of Ipomopsis, which possess a base chromosome number of n= 7 (Grant 1959). Pollen of both D. scabra and D. grantii is blue, with a thick striate-reticulate exine; seeds are minute; and a well-developed corolla tube (6–9 mm long; longer than the calyx) is present. This differs from all members of Giliastrum, having yellow, pertectate pollen grains, larger seeds, and a very short corolla tube (less than 5 mm long; shorter than the calyx).

Dayia is the subject of active research. Evidence in hand supports the expansion of Dayia to include three additional species. This being the case, the information here will soon be obsolete, as the generic description will need to be modified to account for these additional species and the key (below) will also change. These changes are expected soon!

Key to species currently included in Dayia

  1. Anthers mostly included, 1 or 2 barely exserted from the corolla; corolla lobes pale blue, throat pale blue to white, streaked with purple; apex of ovary bearing glandular trichomes; leaves soft, pliable or flaccid Dayia scabra
  2. Anthers well exserted from the corolla; corolla lobes deep blue, throat yellow; leaves more or less rigid D. grantii