Eschscholzia androuxii Still, 2014

Still, Shannon M., 2014, Two new desert Eschscholzia (Papaveraceae) from southwestern North America, PhytoKeys 35, pp. 45-56 : 46-48

Eschscholzia androuxii Still sp. nov. Figs 1 -3

Type.

UNITED STATES, California: Riverside County, just south of entrance sign to Joshua Tree National Park heading north on Cottonwood Springs Road from US Interstate-10, [33°41.188'N, 115°48.103'W], 610 m alt., 14 Feb 2008, Shannon M. Still 258A with Jennifer Still and Charles Still (holotype: DAV!).

Diagnosis.

Eschscholzia androuxii is similar to Eschscholzia minutiflora subsp. twisselmannii C. Clark & M. Faull but with ultimate lobes of the dissected leaves more numerous and narrower than Eschscholzia minutiflora subsp. twisselmannii. Eschscholzia androuxii is similar to Eschscholzia minutiflora subsp. minutiflora S. Watson and Eschscholzia minutiflora subsp. covillei (E. Greene) C. Clark but with larger flowers and consistently appearing, pronounced black-blue or darkened anthocyanin area or spot basipetally located on the fused filament bases of the stamens. Eschscholzia androuxii differs from Eschscholzia papastillii and Eschscholzia parishii with the aforementioned stamen spot and basal foliage that appears more compact in habit.

Description.

Annual herb, erect or spreading with a basal rosette of leaves from a taproot. Leaves highly ternately-dissected into a great number of ultimate lobes, which may number to 100 on larger specimens. Leaves glaucous-green with ultimate lobes more rounded than pointed. Basal leaves are 3-11 cm long and 0.8-3.2 cm wide and held on a petiole comprising 2/3 the entire leaf length. Younger plants will have fewer ultimate lobes and shorter, narrower leaves. Inflorescence with few flowers held above the foliage and to 4 dm above the ground. Leaves on the inflorescence are 2-20 mm long and are divided into 2-23 ultimate lobes. Buds nodding and 4.5-11.5 mm long with an apiculate bud tip less than 25% of the total bud length. Less mature buds may be shorter than average with a longer bud tip by percentage. Flowers held upright and are yellow with four petals 10.5-23 mm long. Each flower has 20-36 stamens fused at the base. There is a darkened area or patch, often black-blue, located at the fused filament bases of the stamens. Receptacles obconic and 2.5-5.5 mm long and 1.1-3 mm wide and often have a scarious inner hyaline rim. Fruit 3.5-6.5 cm long with 10-12 nerves, dehiscing at maturity. Seeds with reticulate ridges.

Distribution

( Fig. 3 ). Found in and around Joshua Tree National Park in both Riverside and San Bernardino counties of California.

Habitat and ecology.

Desert washes, flats, and slopes in coarse, sandy soil.

Phenology.

Eschscholzia androuxii typically flowers between late-February and early-May but may flower earlier in the season, including in the fall, during years with a summer rain and cool fall temperatures.

Etymology.

The species is named for James André and Tasha La Doux, two desert botanists and friends that helped point to the problems with desert Eschscholzia identification.

Suggested common name.

Joshua Tree poppy.

Conservation status.

As this is a new taxon it has yet to be considered for conservation status. Due to the limited range and low number of occurrences, the author suggests the California Native Plant Society consider this taxon for listing as a rare plant.

Specimens examined.

U.S.A. California: Riverside Co.: White Water, Apr 1907, S.B. Parish 6103 (DS!); slope of hill at west side of mouth of Whitewater Canyon, 18 Mar 1962, D.W. Kyhos 62-43 (DS!); Cottonwood Pass, Joshua Tree National Monument, 19 Mar 1949, C. Francis Shutts 58 (ASU!, DES!); Coachella Valley, Desert Hot Springs, N of intersection of Pierson Blvd. and Atlantic, north of flood control ditch, 6 Apr 2001, A.C. Sanders, Mitch Provance & T.B. Salvato 23939 (DES!); Joshua Tree National Park, [33°41.18333'N, 115°48.1'W], 15 Feb 2008, Shannon M. Still, Jennifer R. Still, & Charles M. Still 258B (DAV!); id., Cottonwood Wash on west side of road, [33°41.21299'N, 115°48.15100'W], 22 Feb 2009, Shannon M. Still 444 (DAV!); id., [33°41.833'N, 115°48.17598'W], 3 Mar 2009, Shannon M. Still & Robert Lee 457 (DAV!); id., [33°50.22799'N, 115°45.174'W], 28 Mar 2009, Shannon M. Still, Steven M. Still & Carolyn M. Still 512 (DAV!); San Bernardino Co.: 1.4 mi N of Yucca Valley on road to Lucerne Valley. About 19 mi west of town of Twentynine Palms, 6 Apr 1957, John H. Thomas 6627 (DS!).

Discussion.

This new taxon has a darkened area basipetally located on the stamen filaments ( Fig. 1e ), which are fused at the base. Eschscholzia minutiflora subsp. twisselmannii also has regularly occurring stamen spots, but only on approximately 70% of specimens examined. No other closely related taxa have these stamen spots. The flower size for this new species is similar to that of the diploid Eschscholzia minutiflora subsp. twisselmannii but larger than both the hexaploid Eschscholzia minutiflora subsp. minutiflora and the tetraploid Eschscholzia minutiflora subsp. covillei. The petal size for Eschscholzia minutiflora subsp. covillei, described in Flora of North America as 6-18 mm long, does overlap with the petal size of Eschscholzia androuxii , with petals 10-23 mm long. But more recent morphological study of the genus ( Still 2011, Still in preparation) indicates that the petals in Eschscholzia minutiflora subsp. covillei range from 4.5-12.5 mm. The reason for this discrepancy may be that some of the larger-flowered Eschscholzia minutiflora subsp. covillei specimens are actually the new taxon, Eschscholzia androuxii . The Joshua Tree poppy has an overlapping range with several species but is found only in Riverside Co. and the southern part of San Bernardino Co. and not much further north or south of Joshua Tree National Park. The range does not overlap, and there are more basal leaf ultimate lobes, than with Eschscholzia minutiflora subsp. twisselmannii. The tips of the basal leaf ultimate lobes are more rounded ( Fig. 1a ) than what is found in either Eschscholzia parishii or Eschscholzia papastillii ( Fig. 4a ), and Eschscholzia androuxii has three times the number of cauline leaf ultimate lobes ( Fig. 1b ) as these two taxa.

Figures

Figure 1. Illustrations of leaves, buds and flowers of Eschscholzia androuxii. A Basal leaf B Cauline leaf C Bud D Petal E Stamens showing diagnostic anthocyanin spot at base of the fused filaments.

Figure 3. Distribution map showing the range for the two new Eschscholzia. Eschscholzia androuxii is represented by right-slanting cross-hatching. Eschscholzia papastillii is represented by left-slanting cross-hatching.

Figure 4. Illustrations of leaves, buds and flowers of Eschscholzia papastillii. A Basal leaf B Cauline leaf C Bud showing widened receptacle D Enlarged receptacle with expanded receptacular rim common in the species E Petal F Stamens lacking the anthocyanin spot at base of the fused filaments common to Eschscholzia androuxii.