A Revision of the Allium Fimbriatum ( Alliaceae ) Complex

Allium fimbriatum in California and northern Baja California causes frequent difficulty in identification. The species, as defined by Ownbey, comprises nine varieties and is characterized by great morphologic diversity. No single character or suite of characters separates this species from others in the A. sanbornii alliance. This investigation was undertaken to survey the large number of herbarium specimens that have accumulated since Ownbey's study and to observe all of the taxa in the field or garden, something not accomplished by Ownbey. Orientation of the perianth segments, visible only in living material, along with shape and presence or absence of denticulation, is valuable in distinguishing between taxa. Characters of the ovarian crest processes, including the presence or absence and location of surface ornamentation and the degree to which the margins of the processes are denticulate or fimbriate, are also important. Based on these characters, along with habit, edaphic preference, and geographic distribution, seven species and two varieties are recognized. Of these, A. abramsii, A. denticulatum, A. diabolense, A. munzii, A. parryi, and A. sharsmithae were previously classified by Ownbey as varieties of A. fimbriatum. Chromosome numbers (all n = 7) are reported for each taxon. Line drawings of representative ovarian crests and perianth segments, a key, and distribution maps of the taxa are presented.


INTRODUCTION
Allium is a difficult genus in western North America; many taxa are rarely collected.Furthermore, characteristics visible in living specimens are often obscured or destroyed by pressing.As has been pointed out in a number of recent papers (McNeal and Ownbey 1982;Mortola and McNeal 1985;Denison and McNeal 1989;McNeal 1992), these factors have combined to cause earlier investigators to overlook critical features and to misinterpret geographic variation in a number of species.This is particularly true of Allium fimbriatum S. Wats.which, as circumscribed by Ownbey, consists of nine varieties.
Alliumfimbriatum sensu Ownbey was one of a group ofNorth American species referred to the A. sanbornii alliance by Ownbey (Saghir et al. 1966).Species in this alliance are characterized by a solitary terete leaf and an ovarian crest formed by six prominent and nearly triangular flattened processes, two near the summit of each of the three ovary lobes.It is the most distinctive of the nine alliances proposed by Ownbey.However, A.fimbriatum sensu Ownbey is confusing because no single feature or suite of features serves to define the species nor to separate it from other members of the alliance.This investigation revealed distinct morphological characters among Ownbey's varieties of A. fimbriatum, including shape and orientation of the perianth segments, ornamentation on the ovarian crests, and habit, as well as differences in edaphic and geographic distribution.When taken together these differences suggest that seven of Ownbey's varieties are not as closely related to each other nor to A. fimbriatum as he believed.These seven taxa are recognized here as distinct species (A. abramsii, A. denticulatum, A. diabolense, A. munzii, A. parryi, and A. sharsmithae).
Allium fimbriatum was described by Sereno Watson (1879) from a specimen consisting only of flowers and pedicels collected by Palmer along the Mojave River in southern California.In the same paper he also described A. parryi from San Bernardino County.Jepson (1922) described two new varieties of A. fimbriatum, var.mohavense from the Calico Mountains in San Bernardino County and var.aboriginum from Lake County and the southern Sierra Nevada.The specimens he cited from the southern Sierra Nevada were a mixture of var.
fimbriatum and two other taxa that Ownbey later (in Munz and Keck 1959) described as varieties abramsii and denticu/atum.Eastwood (1938) Traub (1972); the epithets parryi and purdyi were not validly published until Traub (1967) published them as subspecies of A. fimbriatum.These varieties were attributed to Ownbey and Aase in Munz and Keck (1959), presumably because the two authors were planning to publish a treatment of the A. sanbornii alliance; they had published an earlier paper on the A. canadense alliance (Ownbey and Aase 1955).No such paper was published and all of the specimens I have seen were annotated only by Ownbey.For purposes of attribution therefore, I refer to these as Ownbey ex Traub.

MA TERIAI.S AND METHODS
As part of a revision of Allium in California, I studied the specimens of major American and Californian herbaria (CAS, CHSC, CPH, DA V, DS, GH, JEPS, MO, NY, POM, RSA, UC, US, WS).In addition, I made field observations of all but one of the taxa (A.munzii) treated in this paper and, where possible, grew them in Stockton, California.The exception, A. munzii is a very rare species from an area of southern California that is being rapidly urbanized.Collections of this species were made by Steve Boyd (RSA) from each of the seven known populations, and bulbs of each were grown at Stockton.Chromosome counts of all taxa were made using aceto-orcein squashes of pollen mother cells from fresh flower buds.

RESULTS
In the course of this investigation, all of the taxa treated were collected.However, for A. munzii and A. sharsmithae, the number of sheets of specimens in herbaria is still less than 30.The field studies and cultivated plants gave ample opportunity to observe such features as condition and length of the leaf at anthesis, orientation and shape of the perianth segments, and degree and type of denticulation of the margins of the crest processes.The results of these observations are found in the taxonomic treatment which follows.The measurements given for each taxon in the taxonomic treatment represent both new specimens collected during the investigation and over 1500 specimens from the herbaria listed above.
Field observation indicates that all taxa in this investigation are well adapted to summer drought and irregular amounts of rainfall from year to year.Flowering seems to be correlated with late autumn and early winter rains.In drought years most plants will produce a leaf but very few flower, in some cases plants will initiate flower buds but these wither prior to anthesis.When rainfall is heavier almost all plants in a population flower successfully.
In all taxa the meiotic chromosome number was found to be n = 7, the most common number for North American species (McNeal 1969, Mingrone 1968, Ownbey and Aase 1955).Vouchers for chromosome counts are given in the Appendix.

TAXONOMIC TREATMENT
In the following key, characters are given that will allow the reader to separate members of the A. sanbornii alliance from other North American species and to distinguish the other species in the alliance (indicated by brackets) from those treated here as part of the A ..fimbriatum complex.Bulbs ovoid to ± subglobose, l 0-14 mm, outer coats reddish brown, inner coats pale brown to white, bulb coat reticulation none or with two or three rows of vertically oriented cells just above the roots; scape 5-18 em, narrowing toward the base, becoming nearly filamentous and easily broken; leaf 1.5-2 times the scape; umbel 5-30 flowered; pedicels 5-20 mm; straight, erect to spreading; perianth segments 9-17 mm, rose-purple, lanceolate, acute, plane, erect, ±flaring at the tip, the inner, at least, minutely denticulate; ovarian crests entire, emarginate, or with the margins minutely papillose, ovary surface papillose between the processes, stigma trifid, spreading or reflexed (Fig. 1-3).Chromosome number n = 7.
DISTRIBUTION (Fig. 1  Allium denticulatum is similar to A. fimbriatum var.fimbriatum in habit and flower color.It differs in its denticulate perianth segments and its entire, emarginate or papillose margined rather than fimbriate or laciniate crest processes.It is also similar to A. fimbriatum var.mohavense in habit and the papillae on the ovary surface between the crests, but differs in flower color and again in its denticulate perianth segments and the margins of the crest processes.Its geographic distribution, while contiguous to those of A. fimbriatum vars.fimbriatum and mohavense, apparently does not overlap with either taxon.Bulbs ovoid to subglobose, 10-15 mm, outer brown to gray, inner coats white to pink, bulb coat reticulation none or with obscure quadrate markings, usually with 2-3 rows of obvious vertically oriented cells just above the roots; scape 5-15 em, not narrowed toward base, firmly attached to bulb; leaf 2-3 times the scape; umbels 6-40 flowered, pedicels 6-15 mm, straight, erect to spreading; perianth segments 8-15 mm, rose-purple, linear to lanceolate, the outer longer and broader than the inner, ± strongly spreading, reflexed in the outer 1 13, the inner erose-denticulate, at least in the proximal half, often crisped, the outer entire to minutely denticulate; ovarian crest processes usually entire, sometimes emarginate or minutely denticulate on the margins, stigma trifid, spreading (Fig. 6-9).
Chromosome number n = 7. DISTRIBUTION (Fig. 1 7): East-central Madera Co. to central Tulare Co., California.Disintegrated granite on the western slope of the Sierra Nevada, from 900 to 3000 m.Flowering mid-May to mid-July.
Allium abramsii is a very distinctive species, differing from A. fimbriatum in its brown to gray outer bulb coats and white to light pink inner coats, its reflexed somewhat erose perianth segments with the inner sometimes crisped, and its ovarian crest processes which are usually entire or nearly so.Two populations are known in Tulare Co. near the northernmost population of A. parryi, but it is otherwise geographically distant from other members of the A. sanbornii alliance.
Ownbey's report (in Munz and Keck 1959) of reticulate outer bulb coats was based on a specimen [M.Baker 4406a (UC!)] from Tulare Co. that consists of scapes, leaves, and flowers of A. abramsii with no attached bulbs and separate bulbs that Baker apparently dug up in the same location.The bulbs belong to A. obtusum Lemmon var.obtusum, a species with a distinctive bulb coat reticulation pattern (Mortola and McNeal 1985).Bulbs ovoid to subglobose 10-18 mm, outer coats reddish brown, inner coats lighter brown, bulb coat reticulation none or with 2-3 rows of vertically oriented cells just above the roots; scape 4-17 em, not narrowed toward base, firmly attached to bulb; leaf± 2 times the scape; umbels 5-50 flowered; pedicels 6-19 mm, straight, erect to spreading; perianth segments 10-18 mm, dark red-purple, lance-linear to narrowly elliptic, acute to attenuate, plane, erect, flaring at the tip, entire; ovarian crest processes entire to shallowly emarginate, papillate on the surface, particularly near the tips, stigma trifid, reflexed (Fig. 10, 11 ).Chromosome number n = 7. DISTRIBUTION (Fig. 17 Allium sharsmithae is a highly restricted serpentine endemic that differs from A. fimbriatum in its generally larger flower size and its distinctive papillate crest processes.The papillae are most easily seen in fresh material or in flowers that have been reconstituted in hot water.Allium sharsmithae replaces A. fimbriatum in the Mt.Hamilton range where its distribution overlaps A. diabolense, from which it differs in its flower size, color, and papillate crest processes.Bulbs ovoid to subglobose, 8-14 mm, outer coats reddish-brown, inner coats lighter brown, bulb coat reticulation none or with 2-3 rows of vertically oriented cells just above the roots; scape 5-20 em, not narrowed toward the base, firmly attached to bulb; leaf± 1.5 times the scape; umbel 8-50 flowered; pedicels 6-20 mm, in the infructescence the outer longer and curving upward; perianth segments 6-9 mm, white or with pink midveins, older flowers becoming red; lanceolate to lance-ovate, acute to attenuate, entire, plane, straight or flared at the tip; ovarian crest processes entire or emarginate, sometimes finely and irregularly dentate, stigma trifid, spreading or reflexed.Chromosome number n = 7. DISTRIBUTION (Fig. 17): Scattered locations in the southern Sierra Nevada of Tulare Co., California and in the San Bernardino, San Jacinto and Cuyamaca mountain ranges of Southern California.It is also known from one collection in northern Baja California (not on map).Sandy or more commonly clay soils from 900 to 2150 m.Flowering late April to mid-July.
Allium parryi differs from A.fimbriatum in its long, distinctively curved fruiting pedicels that result in an almost flat-topped umbel in some plants.It also differs in having entire or nearly entire crest processes.The flower color makes it resemble :2mm Fig. [10][11][12][13][14][15][16][12][13][14][15][16]12,14: ovary;11,13,16: inner perianth segment; 15: outer perianth segment.Allium abramsii, A. denticulatum, A. munzii, A. parryi, and A. sharsmithae.A. munzii of the south coast and A. diabolense of the central and south coast ranges, from which it differs in the shape of its perianth segments and again in its curved pedicels.Bulbs ovoid to ±subglobose, 10-17 mm, outer coats red-brown, inner coats pale brown to white, bulb coat reticulation none or with two or three rows of vertically oriented cell just above the roots; scape 10-37 em, not, or only slightly, narrowed toward the base, firmly attached to bulb; leaf 1.5-2 times the scape; umbels 6-75 flowered; pedicels 6-20 mm, straight, erect or spreading; perianth segments 6-14 mm, dark rose-purple to white, lanceolate to ovate, acute to obtuse, erect, straight or slightly flaring at the tip, entire, plane; ovarian crest processes finely dentate to deeply laciniate, rarely absent in var.purdyi, stigma trifid, spreading to reflexed.Chromosome number n = 7. DISTRIBUTION: Lake Co., California, south in the coast ranges to San Diego Co., east across the Tehachapi Mts. to the Mojave Desert, and south to northern Baja California.
Allium fimbriatum is closely related to A. sharsmithae.It differs in its finely dentate or, more commonly, fimbriate or laciniate, nonpapillate crest processes and broader perianth segments.It is also close to A. denticulatum which has papillae on the ovary surface, but has narrower, irregularly denticulate inner perianth segments and mostly entire or papillate ovarian crest process margins.Scape 10-20 em; umbel6-35 flowered; perianth segments 9-14 mm, dark rosepurple, the tips flaring; ovarian crest processes finely and irregularly dentate to fimbriate or laciniate (Fig. 12,13).
DISTRIBUTION (Fig. 18): California, Lake, and Napa counties, disjunct south to San Benito and Monterey counties, and from there south in the Coast and Transverse ranges to San Diego Co. with one collection from Baja California (not on map); also found along the San Joaquin Valley and desert slopes of the southern Sierra Nevada and Tehachapi mts.and the western desert ranges of Kern and San Bernardino counties.Clayey, volcanic and serpentine soils, from 300 to 2700 m.Flowering late April through June Jepson's var.aboriginum is based on the holotype from Lake Co., California, and several specimens from the "southern Sierra Nevada from Fresno Co. to Tulare Co."These latter specimens all belong to A. abramsii or A. denticulatum and differ from A. fimbriatum in the characters previously discussed.The holotype, on the other hand, is clearly different from the southern Sierra Nevada material and belongs to A. fimbriatum var.fimbriatum.
Jepson's A. anserinum is more puzzling: the holotype consists only of flowers that are dark rose-purple and have trifid stigmas and fimbriate to laciniate crest processes.As such it fits into A. fimbriatum var.fimbriatum.The label reads simply "Goose Lake Valley, R. M. Austin, May 1894."It is likely that the specimens were neither collected by Mrs. Austin nor collected in the Goose Lake Valley in Modoc County.I have been unable to locate any other Goose Lake that is in or near the range of the species and speculate that this is one of those cases where herbarium labels have been mixed before specimens were mounted.
Alliumfimbriatum var.purdyi differs from var.fimbriatum in its generally more robust habit, its white to lavender flowers, and in the fact that individual specimens in populations may lack the ovarian crests entirely.I would have suggested that this variety deserved recognition as a species except for specimens, including the type, which are clearly intermediate.There seems to be an altitudinal gradient between the two varieties.Specimens from the summit on highway 20 at the border between Lake and Colusa counties and areas along the ridges to the north and south are somewhat smaller and have lavender flowers, thus resembling var.fimbriatum.Specimens from lower elevations along Bear Creek about 4 km to the east are more robust and have white flowers.Scape 10-25 em; umbel 12-60 flowered; perianth segments 8-14 mm, white, pink or light lavender; ovarian crest processes deeply laciniate with papillae and sometimes larger outgrowths on the ovary surface between the processes (Fig. 14-16).
DISTRIBUTION (Fig. 18): In the western Mojave Desert, California, from the southern Owens Valley, Inyo Co. to the base of the San Bernardino Mts., San Bernardino Co. Sandy soils on desert slopes from 750 to 1400 m.Flowering mid-April to June.
Alliumfimbriatum var.mohavense is restricted to the floor and lower mountain slopes of the western Mojave Desert.It is distinct from var. fimbriatum except in an area along the north base of the San Bernardino Mountains where the distribution of the two is contiguous and where specimens show intermediate characteristics.These specimens have lavender to purple flowers and ovarian crest processes that are dentate to somewhat laciniate, without any additional outgrowths from the ovary surface.It may be that these specimens belong to var.fimbriatum.However, by placing them here their intermediate nature and the close relationship between the two varieties is accented.Bulbs ovoid to subglobose, 10-16 mm, outer coats red-brown, inner coats pale brown to white, bulb coat reticulation none or with two or three rows of vertically oriented cells just above the roots; scape 7-20 em, not or only slightly narrowed toward the base, firmly attached to bulb; leaf 1.5-3 times the scape; umbels 10-50 flowered, pedicels 7-20 mm, straight, erect to spreading; perianth segments 6-10 mm, white with pink mid veins and sometimes pink tips, lance-ovate to ovate, obtuse, erect, plane, entire; ovarian crest processes emarginate to laciniate, rarely entire, stigma trifid, spreading to reflexed.Chromosome number n = 7. DISTRIBUTION (Fig. 18): Central and South Coast ranges of California from Alameda Co. to Santa Barbara and Ventura counties.Apparently restricted to serpentine soils from 500 to 1500 m.Flowering early May to mid-June.
Allium diabolense differs from A. fimbriatum var.fimbriatum in its generally smaller flowers and broader, obtuse, white perianth segments.While its flower color resembles that of other taxa described here, it otherwise seems most closely related to A. munzii, from which it differs in its longer leaves, narrower perianth segments, and generally more dissected crest processes.
): Mt.Hamilton Range in Alameda, Stanislaus, and Santa Clara counties.Restricted to serpentine soils from 450 to 1150 m.Flowering late April to mid-May.
Munz and Keck 1959), recognizing that it was related to A. fimbriatum and A. parryi, but not speculating on these relationships.When Ownbey revised the group (inMunz and Keck 1959), he reduced A.
7): Eastern Kern Co. and north-central Riverside Co., California.Also known from single collections near Granite Well in eastern San Bernardino Co. and Mt.Pinos in western Kern Co. Sandy soils on desert slopes, from 900 to 2500 m.Flowering late April to early June.