Dayia grantii J. M. Porter, Aliso 19: 72, 73. 2000. TYPE.—Mexico, Baja California Sur, Vizcaino Desert, 1.5 mi. N of San Hipolito turn-off, valley bottom at W foot of Cerro Prieto, 26 March 1991, K. Heil & J. M. Porter 6478 (holotype: RSA!; isotypes: BRY!, SJNM!).
Erect herbaceous perennials with woody base or more frequently sub-shrubs, (18)30-–60 cm high and 20–50 cm wide, much branched, the young parts glandular-pubescent with 2–8(10) celled trichomes mostly less than 0.10–0.33 mm long, each tipped with a unicellular or multicellular yellowish gland. Woody base to 8.5 mm thick, the bark light to dark tan or gray, spliting into a network of narrow vertical strips. Branches ascending, branching pattern axillary along the primary axis, ultimately sympodial in the inflorescence, the branches flowering terminally, 8–30 cm long 1–4 mm thick the first year, tan to strongly anthocyanic becoming gray, chlorophylous terminally, subterete; internodes 0.5–55.3 mm long, mostly 5.0–12.0 mm, generally shorter than the leaves. Primary leaves alternate or rarely sub-opposite, pinnatifid to nearly palmate, 8.0–32.6 mm long, gradually reduced in size in the inflorescence, rachis 0.6–1.3 mm wide, (1)2–4 pairs of opposite to sub-opposite lobes, 5.0–12.6 mm long, 0.6–1.1 mm wide, often two sets of lobes are located at the base of the mucronate tipped leaf, sparsely glandular. Inflorescence densely glandular puberulent, composed of reduced (1-) 2-flowered cymes, forming a thyrsoid inflorescence. Pedicels erect to spreading, pedicel of terminal flower 1.0–3.2 mm long, 0.35–0.60 mm thick, pedicel of lateral flower 5.0–10.5 mm long, 0.30–0.60 mm thick. Calyx 5.5–7.5 mm long, 1.7–3.0 mm in diameter at the sinuses, cylindric, tapering to a rounded base, densely glandular externally, less so internally, tubular for 3.3–4.8 mm (the lower 2/3 to 3/4), segments (lobes) equal, erect or somewhat out-curved, 1.2–3.0 mm long, triangular lanceolate, pungent-acuminate, aristate, with three primary veins within, scarious margined except near the apex; sinuses v-shaped, the scarious intervals about equal to the chlorophyllous costae, generally not rupturing in fruit. Corolla funnelform to salverform, 14.0–22.0 mm long, glabrous both externally and internally, pale to deep blue, with a distinct yellow center, tube shorter than lobes, straight, 6.0–9.0 mm long, ca. 3.0 mm in diameter at 1/2 length, slightly flaring at the orifice, 4.0–5.0 mm wide; lobes 8.5–12.0 mm long, 6.0–9.5 mm wide at 1/2 length, oval to oblong or nearly orbicular, entire to emarginate, muriculopapillose within, the lobes convolute in bud, in anthesis spreading, with (15)17–22(24) close-spaced parallel veins per lobe, the veins not connected in the lobes. Filaments glabrous, 13.5–17.6 mm long, sub-equally attached in the upper tube, the filaments superficially to distinctly adnate to the corolla tube, filaments declinate, flowers protandrous; anthers 3.5–4.5 mm long, 0.6–0.8 mm wide, linear to linear-ovate, erect to versitile, mostly simultaneously dehiscing as the corolla lobes open, along the theca from the terminal point and downward, well exserted from the corolla tube but slightly shorter than the lobes. Pollen grains suboblate to sheroidal; apertures zonate, 5–7 colporate; exine striate, the reticulum radiating from the apertures like lines of force in a magnetic field. Nectary disk green, ca, 2 mm wide shallowly cupped, the margin regularly undulate to form erect lobules opposite the calyx segments and spreading ones opposite the corolla lobes. Ovary three celled, 3.0-4.0 mm long, ca.1.0 mm wide at the base, glabrous; style 10.0–15.0 mm long, subequal to longer than the anthers; stigma lobes linear, acute, 1.5–2.0 mm long, spreading when receptive; ovules anatropous, unitegmic, axial placentation, 24–48 per cell. Fruit a capsule, obovate, tan to golden brown, often suffused with purple, 6.0–9.0 mm long, 2.5–3.5 mm in diameter, apex acute, loculicidally dehiscing, valves slightly recurving to erect, fruit shorter than the calyx. Seeds 12–46 per cell, minute, ca. 1.2 mm long, 0.6 mm wide, ovoidal, nearly round in cross-section, golden to pale tan, possessing no vestiges of a wing, the outer testa with hygroscopic mucilage cells, producing copious fibrils when wetted. Embryo achlorophyllous, surrounded by a more or less thin layer of endosperm, the cotyledons ovate, equal to or slightly longer than the radical. Chromosomes: x=9. (grantii: honoring Verne E. Grant, botanist, geneticist, student of Polemoniaceae).
Dayia grantii apparently is endemic to a very small region of the Vizcaino desert, along the western coast of northern Baja California Sur. It is known only from the type locality, at the western foot of Cerro Mesa (a.k.a. Cerro Prieto) between San Hipolito and Punta Prieta, 24 km south of Ciudad Bahia Ascuncion. This species occurs along a wash and on adjacent alluvial slopes, associated with Encelia palmeri, Fouqueria dugettii, Jatropha cinera, Euphorbia miser, Bursera hindsiana, and Krameria sp., at approximately 50 ft. elevation. Flowering occurs in (December) February through March (April) in response to winter rains, and again sporadically through the summer in response to the less frequent summer rains.
Representative specimens examined.—MEXICO, BAJA CALIFORNIA SUR: Vizcaino Desert, between Cerro Prieto and Punta Prieta, near San Hipolito, 19 March 1950, H. S. Gentry 8850 (ARIZ, RSA); 1.5 mi. N of San Hipolito turn-off, valley bottom at W foot of Cerro Prieto, 26 March 1991, K. D. Heil & J. M. Porter 6478 (BRY, RSA, SJNM); 1.5 mi. N of San Hipolito turn-off, valley bottom at W foot of Cerro Prieto, 15 March 1994, J. M. Porter 11324 (RSA).
A self-incompatible species, based on ex situ crossing studies, the flowers of Dayia grantii open during the morning and remain open for several days. Observations of insect visitation are limited; but, butterflies, anthophorid bees, and bombilid beeflys frequent flowers.
Errata.—The DNA studies of Johnson et al. (1996) and Porter (1996) included "Gilia scabra" in their analyses. Following the nomenclatural changes provided here, the DNA sample used in these studies actually represents Dayia grantii.