Two new desert Eschscholzia (Papaveraceae) from southwestern North America

Abstract Two new species of Eschscholzia are described. Both are found in the deserts of California and one extends outside the state boundary into Arizona. Eschscholzia androuxii Still, sp. nov. is found mainly in and around Joshua Tree National Park in Riverside and San Bernardino counties. Eschscholzia papastillii Still, sp. nov. is found from the northern Mojave south through Joshua Tree National Park to central Imperial County. Both are annuals found in coarse, sandy soil and have yellow flowers typical of desert Eschscholzia. Eschscholzia papastillii has an expanded receptacular rim similar to that of Eschscholzia californica. Eschscholzia androuxii has anthocyanin bands around the stamen filaments.


Introduction
Eschscholzia Cham. (1820) is a genus in the Papaveraceae tribe Eschscholtzieae along with the genera Hunnemannia Sweet and Dendromecon Benth. Th e type genus is native to the mainland and islands of western North America in both the United States and Mexico, but the type species, Eschscholzia californica Cham. has invaded Mediterranean regions around the world. Th e taxa are native to mesic and xeric landscapes. Recent treatments for Eschscholzia (Clark 1997, Roberts 1989) recognize 12 species and several subspecies for a total of 16 taxa. Recent phylogenetic work (Still and Potter 2013) indicates 18 distinct taxa. While the genus is fairly small, there are nearly 198 taxon names and 168 type specimens, with the majority described by EL Greene (1905). Th e majority of described taxa are synonymous with E. californica.
All taxa are herbaceous annuals or perennials with taproots and basal rosettes. Th e leaves are ternately-dissected 2-many times and range from bright green, dark green to glaucous grey-green. Flowers are bisexual, have two sepals fused into a single cap structure, four petals and many stamens. Th e sepals fall from the fl ower upon opening. Th e fl owers are yellow, orange or can be yellow with an orange basipetal spot on each petal. Th e desert taxa of the genus can be diffi cult to identify (personal experience) and this resulted in further morphological and molecular examination of Eschscholzia (Still 2011, Still andPotter 2013). In the course of study, two new taxa were discovered among Eschscholzia native to desert regions (Still 2011). Th ese two taxa exhibited both morphological traits and mutations in nucleotide sequences from nuclear and plastid regions that distinguish them from one another and from all previously described species of Eschscholzia. Th e two new taxa are here described as new species. Diagnosis. Eschscholzia androuxii is similar to E. minutifl ora subsp. twisselmannii C. Clark & M. Faull but with ultimate lobes of the dissected leaves more numerous and narrower than E. minutifl ora subsp. twisselmannii. Eschscholzia androuxii is similar to E. minutifl ora subsp. minutifl ora S. Watson and E. minutifl ora subsp. covillei (E. Greene) C. Clark but with larger fl owers and consistently appearing, pronounced black-blue or darkened anthocyanin area or spot basipetally located on the fused fi lament bases of the stamens. Eschscholzia androuxii diff ers from E. papastillii and E. parishii with the aforementioned stamen spot and basal foliage that appears more compact in habit.

Eschscholzia androuxii
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. Infl orescence with few fl owers held above the foliage and to 4 dm above the ground. Leaves on the infl orescence 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 fl ower has 20-36 stamens fused at the base. Th ere is a darkened area or patch, often black-blue, located at the fused fi lament 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, fl ats, and slopes in coarse, sandy soil. Phenology. Eschscholzia androuxii typically fl owers between late-February and early-May but may fl ower earlier in the season, including in the fall, during years with a summer rain and cool fall temperatures.
Etymology. Th e species is named for James André and Tasha La Doux, two desert botanists and friends that helped point to the problems with desert Eschscholzia identifi cation.
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. Discussion. Th is new taxon has a darkened area basipetally located on the stamen fi laments (Fig. 1e), which are fused at the base. Eschscholzia minutifl ora 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. Th e fl ower size for this new species is similar to that of the diploid E. minutifl ora subsp. twisselmannii but larger than both the hexaploid E. minutifl ora subsp. minutifl ora and the tetraploid E. minutifl ora subsp. covillei. Th e petal size for E. minutifl ora subsp. covillei, described in Flora of North America as 6-18 mm long, does overlap with the petal size of E. 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 E. minutifl ora subsp. covillei range from 4.5-12.5 mm. Th e reason for this discrepancy may be that some of the larger-fl owered E. minutifl ora subsp. covillei specimens are actually the new taxon, E. androuxii. Th e 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. Th e range does not overlap, and there are more basal leaf ultimate lobes, than with E. minutifl ora subsp. twisselmannii. Th e tips of the basal leaf ultimate lobes are more rounded (Fig. 1a) than what is found in either E. parishii or E. papastillii (Fig. 4a), and E. androuxii has three times the number of cauline leaf ultimate lobes (Fig. 1b)   Diagnosis. Eschscholzia papastillii is similar to E. parishii Greene but with more basal leaf ultimate lobes and more broadly spreading leaves. Eschscholzia papastillii has an enlarged receptacle (Fig. 4d) that is widely-obconic or bell-shaped, and wider at the midpoint of the receptacle than E. parishii, E. androuxii or any of the subspecies of E. minutifl ora, which are usually more obconic or funnel-shaped. Th e expanded receptacular rim of E. papastillii is similar, but typically smaller, than the expanded receptacular rim of E. californica. Eschscholzia papastillii diff ers from E. androuxii and E. minutifl ora with basal foliage that appears less compact in habit.
Description. Annual herb, erect or spreading with a basal rosette of leaves from a taproot. Leaves highly ternately-dissected into 17-70 ultimate lobes with the higher number on larger specimens. Leaves glaucous-green to green with ultimate lobes more pointed than rounded. Basal leaves are 2.7-16 cm long and 0.9-7 cm wide and held on a petiole comprising 2/3 the entire leaf length. Younger plants have few basal leaf ultimate lobes and shorter, narrower leaves. Infl orescence with few fl owers held above the foliage and to 5 dm above the ground. Leaves on the infl orescence are 3-50 mm long and are divided into 1-13 ultimate lobes. Buds nodding to erect and 2.5-16 mm long with an apiculate bud tip greater than 30% 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 5-24 mm long. Each fl ower has 12-32 stamens fused at the base. Receptacles widely-obconic or funnel-shaped to nearly bell-shaped, 3-9 mm long and 1.5-4.7 mm wide. Receptacular rim typically noticeable and often thick but can be scarious, expanded laterally up to 1.2 mm from the top of the receptacle. Th e receptacle often has a scarious inner hyaline rim in addition to the outer rim diagnostic of the species. Fruit 4 -8 cm long with 10-12 nerves, dehiscing at maturity. Seeds with reticulate ridges. Distribution (Fig. 3). Found north to the northern Mojave Desert; south into northern Colorado Desert of San Diego Co., and possibly south along the east side of the Sea of Cortez in Mexico; east to the California-Arizona border (Whipple Mountains); west to the western end of Joshua Tree National Park.
Habitat and ecology. Desert washes, fl ats, and gentle slopes in coarse, sandy soil. Phenology. Eschscholzia papastillii typically fl owers between late-February and early-May but may fl ower earlier in the season, and in the fall, during years with a summer rain and cool fall temperatures.
Etymology. Th e species is named in honor of Dr. Steven Still, my father and mentor and the reason for which I study plants.
Suggested common name. Cryptic desert poppy. Conservation status. As this is a new taxon it has yet to be considered for conservation status. Due to the range and number of occurrences the author does not suggests this taxon be considered for conservation status.