Navarretia miwukensis D.Gowen & L.A.Johnson, 2016

Johnson, Leigh A., Gowen, David, Johnson, Robert L., Brabazon, Holly & Goates, Emily D., 2016, Navarretia crystallina and N. miwukensis (Polemoniaceae): new species endemic to California with affinity for soils derived from pyroclastic deposits, Phytotaxa 257 (3), pp. 249-260 : 256-258

Navarretia miwukensis D.Gowen & L.A.Johnson , sp. nov. ( Fig. 4 )

A species similar to Navarretia crystallina , but distinguished by being less dense with respect to inflorescence trichomes but bearing more conspicuous viscid, short-stipitate glands in the inflorescence, in having bract and calyx lobes with wide, convex bases that taper concavely (i.e., acuminate) versus evenly tapered, long-acute lobes in N. crystallina , and in having greater inequality in the insertion of stamens.

TYPE: — U.S.A. California: Tuolumne County, On pyroclastic rubble and soil above road cut on north side of Hwy 108 just west of hairpin in Lava Drive , 38.02665°N, 120.23697°W, 1159 m, 5 June 2014, L.A. Johnson, R. L. Johnson, Brabazon, & Goates 14-075 (holotype BRY!; isotypes JEPS! RSA! and to be distributed).

Taprooted annuals commonly 3–12(–18) cm tall and 2–15(–30) cm wide. Primary stem erect, generally exceeded in length by secondary stems, with tertiary, and quaternary stems occasionally present; branches ascending to spreading and ± leafless, except for leaves subtending higher order branches; primary stem (terminating in a head) (0)2–5(8) cm, secondary stems (branches) 1–10 in number, 0.1–10 cm, tertiary branches 0.1–8 cm, quaternary branches 0.1–4 cm; tertiary and quaternary branches usually arising directly below or within 1 cm of an inflorescence head; stem and branches reddish-brown, sparsely minutely stipitate-glandular puberulent, the trichomes generally less than 0.25 mm long. Cotyledons two, linear, entire, united at base. Leaves stipitate-glandular puberulent with trichome density and length greatest on the proximal, adaxial surface; leaves at the lowermost 1–2(–3) nodes opposite, linear-filiform, and widened at the point of stem attachment, the proximal nodes often congested with overlapping leaf bases. More distal leaves alternate, entire, or more commonly with 1–3 pairs of linear lobes 1–5(–7) mm long attached along the proximal 3(–5) mm of the leaf, with an elongated, linear terminal segment 1–3 cm long (leaves with lobes along the proximal 1.2 cm of the leaf uncommon; these with lobes alternating, rather than oppositely paired). Inflorescences sparsely to moderately white hairy, prominently glandular, viscid. Inflorescence bracts: outermost 1–2 similar to upper leaves; bracts grade centripetally to having a wide, convex-clasping rachis membranous-margined and achlorophyllous proximally and chlorophyllous distally, shaggy pubescent along the margin, somewhat on the adaxial surface of the bract lobes near their attachment with the rachis, and sparsely on the abaxial rachis base with short glandular trichomes abundant; bracts bear ~ 3 pairs of chlorophyllous lateral lobes co-planer with the central, elongate terminal lobe (short, abaxially diverging lobes on either side of the terminal lobe not observed); lobes entire, short-stipitate glandular; inner bract gradation continues with the rachis widening further, the abaxial rachis surface densely covered in short stipitate glands, and the lateral bract lobes reduced to 2 pairs or even 1 pair, departing from the distal rachis edge; bract lobes acuminate from a broad base, commonly becoming reddish brown with age and may gently recurve. Inflorescences, 1–18(–50) in number, head like, ± spherical, (5–)10(–13) mm in diameter exclusive of bract tips; cymes, composed of a bract and 1 or 2 flowers, subsessile and tightly packed in heads; flowers generally fewer than 20 per head. Flowers: calyces mostly 5.0– 10 mm long, tube ~ 3.2–3.7 mm, costae strongly to somewhat unequal with typically two lobes longer than the other three, lobes entire, acuminate, costae narrowing proximally, narrower at base than the intercostal membrane which is v-shaped at sinus, shaggy hairy on the abaxial calyx tube and adaxial lobes at the tube-lobe junction; corolla narrowly funnel form, glabrous, 5.5–7.0 mm long, lobes 0.9–1.2(–1.4) mm long × 0.4–1.0 mm wide, tube and lower throat yellow, upper throat and lobes pink to white, veins in throat often darkened, tube base expanding and adhering to the fruit apex. Stamen filaments 0.45–1.0 mm long, inserted unequally 0.35–1.4(–1.8) mm below corolla sinuses, included in throat to exserted less than half the length of the corolla lobes; pollen white, apertures pantoporate, acolpate; sexine seimitectate, reticulate, heterobrochate. Ovary three-chambered, style 2–3.4 mm long, stigmatic lobes ~ 0.3 mm long, included in corolla throat. Capsule ~ 2.5 mm long, dehiscing circumcisally around the base with valves splitting upward, leaving capsule base attached to receptacle inside calyx. Seeds (2)–3–8 per locule, medium brown (hue 5YR, value 3, chroma 3), ovoid-angular, ca. 1.0– 1.45 mm long × 0.5–0.7 mm wide, mucilaginous when wet.

Habitat, Distribution, and Phenology:— Navarretia miwukensis occurs in open, sparsely vegetated pyroclastic derived soils often on gently sloping terrain. This taxon is presently known only from Calaveras and Tuolumne counties, California at elevations from 800–1480 meters, and blooms primarily May–June (July).

Etymology:— The specific epithet, literally ‘from Miwuk’, refers to Mi Wuk village, a community within the range of the species nestled among historic gold-rush settlements and named to honor the Me-Wuk Indians that have inhabited this region for centuries.

Additional specimens examined:— U.S.A. California: Calaveras County, Dry hillsides, 18–30 May 1895, Davy 1623 ( UC!) ; West of Avery at the end of a short forest service road off of Avery Sheep Ranch road, 38.19488°N, 120.39969°W, 3695 ft, 17 June 2015, Gowen 1304 (BRY! JEPS!) ; Avery sheep Ranch Road about 1.8 miles west of Avery , 38.19841°N, 120.39886°W, 3567 ft, 3 Jun 2014, Gowen 1258 (BRY!, JEPS!) ; North side of Avery-Sheep Ranch Road , across from forest service road 4N41Y, 38.19697°N, 120.40027°W, 1098 m, 4 June 2014, Johnson et al. 14-067 ( BRY!) ; Table Mountain, ca. 3 air miles ESA of Murphys, on flat volcanic surface west from Ponderosa Way and reached via Camp Nine road. 2700 ft, 20 May 1999, Taylor 17162 ( JEPS!) ; Tuolumne County, 1 mile south of Confidence , 1 June 1940, Hoover 4411 ( UC!) ; Confidence road, about 1.8 miles south of the Confidence store on Hwy 108, 38.02497°N, 120.21114°W, 3929 ft, 19 May 2014, Gowen 1254 (BRY! JEPS!) ; South side of Hwy 108 just east of Sierra Village at Lyons Dam road, 38°4.692’N, 120°9.864’W, 4843 ft, 28 June 2013, Gowen 1230 (BRY! JEPS!) ; South side of Hwy 108 just west of road to Lyons Reservoir , 38.07798°N, 120.16479°W, 1476 m, 5 June 2014, Johnson et al. 14-080 ( BRY!) ; South side of Hwy 108 just south of Twain Harte , 4 June 2014, Gowen 1266 (BRY! JEPS!) ; Southwesterly open slope 1.2 miles from Highway 108, along Cedar Springs Road en route to Cherokee and Tuolumne City , 3480 ft. elevation, 22 May 1971, Wiggins 21151 ( CAS!) ; Corner of Twain Harte Drive and Ponderosa Drive, ca. 1 mile west of center of Twain Harte Village , 3620 ft., 25 May 1971, Wiggins 21251 ( CAS!) ; Twain Harte Post Office, Sierra Nevada, 4000 ft., 3 June 1944, Alexander & Kellogg 3622 ( UC!) .

Notes:—Fresh plants of N. miwukensis are noticeably skunky in odor, and more so than N. crystallina . In addition to a smaller range, more populations of this species are likely at risk to future development than N. crystallina .

Figures

FIGURE 4. Navarretia miwukensis (all Johnson et al. 14-080, BRY). A. Pressed specimen showing plant habit, scale bar = 1 cm. B. Flowering individual in the field, scale bar = 1 cm. C. Pressed flower and inflorescence bract showing trichomes and lobe shape, scale bar = 5 mm. D–E. Inflorescence heads showing fresh flowers, anther presentation, and bracts, scale bar = 5 mm. All photographs by L. A. Johnson.