BRODIAEA SANTAROSAE (THEMIDACEAE), A NEW RARE SPECIES FROM THE SANTA ROSA BASALT AREA OF THE SANTA ANA MOUNTAINS OF SOUTHERN CALIFORNIA

2007·10 MB·English

by  Tom Chester

Madrono, Vol. 54, No. 2, pp. 187-198, 2007
BRODIAEA SANTAROSAE{THEMmKCEK^), A NEW RARE SPECIES FROM THE
SANTA ROSA BASALT AREA OF THE SANTA ANA MOUNTAINS OF
SOUTHERN CALIFORNIA
Tom Chester
CA
1802 Acacia Lane, Fallbrook, 92028
[email protected]
Wayne Armstrong
Life Sciences Department, Palomar College, 1 140 West Mission Road,
CA
San Marcos, 92069
Kay Madore
The Nature Conservancy, Santa Rosa Plateau Ecological Reserve, 22115 Tenaja Road,
CA
Murrieta, 92562
Abstract
Brodiaea santarosae (Themidaceae) is a new species from southwest Riverside County and
immediately-adjacent MillerMountainofSan DiegoCounty, CA. It iseasilydistinguished fromother
Brodiaea species in southern California by its large flowers and distinctive, variable staminodes;
morphological analysis revealed 11 total differentiating characteristics. Brodiaea santarosae occurs
only on or very close to the 8-11 million-year-old Santa Rosa Basalt. It has the smallest range ofthe
southern California Brodiaeas, withjust four known populations occupying only a small portion of
a —40 km- area, plus a fifth small population disjunct by 11 km.
It has been speculated that the B. santarosae population is a hybrid swarm between B.filifolia and
B. orcuttii, based solely on the appearance ofthe staminodes and filaments in selected fiowers. This
speculation wasrejected due to thelack ofsympatry between thethree taxa and because specimens of
B. santarosae have numerous characteristics that are not intermediate between the claimed parent
taxa. In contrast, intermediate characteristics were seen in Fl specimens of B. filifolia X B. oreuttii
discovered in San Marcos, CA, the only location where those species overlap.
We also report extensions to the length characteristics for both B. filifolia and B. orcuttii and
demonstrate that two populations ofB.filifolia previously thought to be hybrids are consistent with
other B.filifolia populations.
Resumen
Brodiaea santarosae (Themidaceae) es una nueva especie del sudoeste del Condado de Riverside y
del monte Millerinmediato-adyacenteen el Condadode San Diego, CA. Esdistinguido facilmentede
las otras especies de Brodiaea del Sur de California por sus flores grandes y staminodes variables y
distintivos; el analisismorfologicorevelo 11 totalesquedistinguencaracteristicas. Brodiaeasantarosae
ocurresolamenteen omuycercadel SantaRosa Basaltde8 11 millonesdeaiiosdeantigiiedad. Tiene
lagamamaspequefiadelas Brodiaeasdel SurdeCalifornia, conapenascuatropoblacionesconocidas
ocupandosolamenteunaporcion pequeiiadeunareade —40 km-, masunaquinto poblacionpequefia
disjunta por 11 kilometros.
Se ha especulado que la poblacion de B. santarosae es un enjambre hibrido entre B. filifolia y B.
orcuttii, basados solamenteen el aspecto delosstaminodes ydelos filamentosen fiores seleccionadas.
Esta especulacion fue rechazada debido a la carencia de sympatry entre los tres taxa y porque los
especimenes de B. santarosae tienen caracteristicas numerosas que no sean intermedias entre los taxa
demandados del padre. En contraste, las caracteristicas intermedias fueron consideradas en los
especimenes Fl del B. filifolia X B. orcuttii descubierto en San Marcos, CA, la unica localizacion
donde esas especies se traslapan.
Tambien divulgamos extensiones a las caracteristicas de la longitud para B. filifolia y B. orcuttii y
demostramos que dos poblaciones del B. filifolia pensaron previamente para ser hibridos son
constantes con otras poblaciones del B. filifolia.
Key Words: Basalt, Brodiaea, California, endemic. Peninsular Ranges, Santa Ana Mountains, Santa
Rosa Basalt, Santa Rosa Plateau.
MADRONO
188 [Vol. 54
Wedescribeherea newspecies ofBrodiaeathat de flores, acuminatus, 0-7 mm; perianthii tubi
has previously been collected by at least six 6.011.3 mm; anthera 5.4—8.9 mm; ovaria 3.5-
different botanists and variously determined as B. 8.2 mm; et styli (includens stigmata) 10.5-
orcuttii (E. Greene) Baker, B. filifolia S. Watson, 17.0 mm.
or a hybrid between the two (see paratype Geophyte; glabrous; conn 15-25 mm high,
specimens cited below, as well as Boyd et al. 25-31 mm wide, producing cormlets at the sides;
1992, 1995). leaves basal, linear, appearing before the
The confusion stems from the remarkable inflorescence; inflorescence scapose, 1-2 scapes
variation in the staminodes in this species. About per coiTn, scape 8.8-36 cm, umbellate;flowers 2- ',
10% of the flowers of this species have no 6 in terminal umbels, erect on pedicels 18-
mm mm
staminodes and long filaments, superficially re- 107 long and 1.1-1.9 wide at distal
sembling the flowers ofB. orcuttii. Approximate- end; bracts at base of umbel, scarious, 6.5-
lsytaamniontohdeers 5a-n1d0%shohratveer sfhiolratmenrtesc,urvsuepderffiilciifaolrlmy 21.10-m3m.9;mcmorolwliadeb,luet-upbuerpl6e.,0-1ca1.m3pamnmu,latleo,besbas6e, Ii
resemblingthe flowers ofB.filifolia. Themajority ascending, 15.4-29.5 mm; ovary green, 3.5-
of the flowers have longer staminodes and 8.2 mm; style including stigma 10.5-17.0 mm,
variable-length filaments, which in the absence stigma 3-lobed, with one lobe usually sHghtly
of quantitative analysis appeared to be hybrids above the other two, distal end of stigma
between those taxa. from 3.0 mm below to 1.4 mm above distal end
The recognition ofthis new species came from of anthers; anthers barely exserted from corolla
a research program of the first two authors on tube, filaments 2.4-8.2 mm, anther sacs 5.4-
hybrids of various Brodiaea species in southern 8.9 mm; staminode present in 90% of ;
!
California, combined with the discovery by the flowers, white to lavender, tapered to tip, free
third author of a large accessible population of portion 0.0-7.0 mm, usually variable in length
this new species. Analysis of that population within individual flowers; fruit loculicidal cap-
revealed that it was not consistent with any sule, with perianth tube becoming thin and
previously-known southern California Brodiaea sometimes splitting at fruit maturity. Flowering
species, nor did it seem consistent with a hybrid May-June.
swarm between any ofthose species. All measurements above are for fresh, not j
This discovery came in time to survey many of pressed, specimens, collected in the relatively dry \
the relevant Brodiaea populations in Riverside year of2006. Measurements might be somewhat
and San Diego Counties during the 2006 season. greater in a wetter year. The flower parts in !
During that survey, we found three specimens dried specimens shrink by roughly 10%. The \
from San Marcos that appear to be true hybrids ranges in the measurements above are exactly
between B. filifolia and B. orcuttii. These speci- the ranges ofour measured values; it is expected
mens were valuable in confirming that this new that the true population range is somewhat
species was not ofhybrid origin. greater.
We were able to obtain and analyze enough Type: USA, California, Riverside Co., Santa
fresh specimens from enough populations to Ana Mountains, Santa Rosa Plateau region: Clay ,
determine that this entity warranted recognition Hill, 0.55 km south-southwest of the northern- I
as a new species that is distinguished from B. most high point ofthe Mesa de Burro; 33.52927° :
filifolia and B. orcuttii by at least 11 separate N, 117.24857" W [NAD27]; 580 m elevation; 15 ,
characteristics. This new species has the smallest June 2006, T. Chester, W. Armstrong, K. Madore \
range ofthe southern California Brodiaeas and is 927 (holotype UCR; isotypes RSA, SD). i
found only on or very close to the 8-11 million- Paratypes: All from USA, CaUfornia, Santa
year-old Santa Rosa Basalt. Ana Mountains. Riverside Co. specimens: Elsi- |
Our analysis also showed that two populations nore Peak, 0.3 km southwest of the Peak,
ofB.filifolia previously thought to be hybrids are 33.60049 decimal degrees N, 117.34514 degrees
consistent with other B.filifolia populations. This W [NAD27], 1045 m elevation, 10 June 2006, T.
adds two protected populations of B. filifolia to Chester, W. Armstrong 918 (UCR), 15 May
the list in U.S. Fish and Wildlife Service (2004). 1992, S. Boyd 7385 (RSA, UCR); Mesa de
These populations were omitted from that list Burro, 23 June 1983, R. Gustafson andG. Wallace '
since hybrids are not as important as pure 2716 (RSA), 25 May 1977," C Davidson 5639
populations for the conservation of the species. (RSA), 0.4 km west of the north end, 17 May j
1988, S. J. Mverss.n. (UCR); Mesa deColorado,
Species Description and Distribution 18 May 1985, R. Thome et al. 60644 (RSA), 27
May 1960, E. Lathrop 5221 (RSA), Via Volcano
Brodiaea santarosae T. Chester, W. Armstrong & Road just north of Avocado Mesa Road, T.
\
K. Madore, sp. nov. (Fig. 1) Chester, W. Armstrong 921 (UCR); Avenaloca i;
Differt a B. filifolia filamenta 2.4^8.2 mm. Mesa, west side, northwest of intersection of i:
Differt a B. orcuttii staminodia praesens in 90% Corona Cala Camino and Avocado Mesa Roads,
I
2007] CHESTER ET AL.: BRODIAEA SANTAROSAE 189
Fig. 1. Comparison offlowers of B. sautarosac with B. orcutfii. B. filifoUa and B. filifolia X B. orcuffii. (A) B.
orcuttii(B) B. filifolia(C) B.filifolia XB. orcuttii. (D-F) B. santarosae. Theflowers shown in D and E arefrom the
same corm. All flowers are to the scale shown in F, and are shown in the same proportion to each otheras for the
median-size flower for each taxon.
MADRONO
190 [Vol. 54
W m
33.49379° N, 117.33178° [NAD27], 720
34.3
elevation, 22 June 2006, T. Chester, W. Arm-
strong 934 (UCR). San Diego County: south SanBernardinoCounty
flank ofMiller Mountain, about upperportion of
Miller Canyon, -730 m, 6 May 1992, S. Bovdet
al. 7289, 7304B {RSAl 7304A (SD). RiversideCounty
Epithet etymology, pronunciation, and common
name. The epithet is for the Santa Rosa Basalt
closely associated with this species. The suggested SantaRosaBasaltArea
pronunciation is san-tuh rose' ee (U.S.), or san-
tuh rose' eye (European). The suggested common
name is Santa Rosa Basah Brodiaea.
Distribution
Brodiaea santarosae is found only in a unique
location in southern California, an area of low
topographic relief that was flooded by the Santa
Rosa Basalt 8-11 million years ago. Its range
mostly, but not entirely, separates the popula-
tions ofB. filifolia and B. orcuttii.
Fig. 2A shows the geographic range of these -117.4 -116.9 -116.4
three species, along with the estimated minimum EastLongitude(degrees)
original extent of the basalt. Populations of B.
orcuttii are found entirely to the south and
southeast ofthe basalt. Populations ofB.filifolia
are found mostly to the north and west of the
basalt, with just a few occurrences to the south,
and only one population within the basalt area.
That population, at the Mesa de Colorado,
occurs at the biggest vernal pool, in heavily-
leached dark vernal pool soils unlike the reddish
basalt-derived soil elsewhere on the basalt; it is
not accompanied there by B. santarosae.
The Santa Rosa Basalt has been dated as 8-11 33.52
million years old (Hull and Nicholson 1992;
v^.^.^-
Hawkins 1970; D. Krummenacher, cited in 33.50 2*
Kennedy 1977). It formerly covered an area of
at least 500 km- (Kennedy 1977), from Elsinore 33.48
OPeaakkMoonutnhteanionrtoh,nttohetheeasMtu,rrtioestoamHeowghbearcekssoauntdh 33.46 RiversideCounty
ofthe Mesa de Colorado on the south, and to the 33.44 SanDiegoCounty
area of Miller Mountain on the west. This is
a minimum extent, estimated simply by taking 33.42
the surviving patches of basalt and assuming -117.40 -117.35 -117.30 -117.25 -117.20
basalt originally was continuous between them. EastLongitude(degrees)
Erosion has removed at least 97% ofthe original
basalt area; the basalt now covers only disjunct Fig. 2. Geographic distribution of B. filifolia (+), B.
areas of about 15 km- (within a region of santarosae (X), and B. orcuttii (O) in southern
apaptpckrhomexsimsautcehlyas4t0hektmw-o) ppaltucsheas afteEwlsvienroyresPmeaalkl amCtailniRfiSomrAnu,ima,SoDrUigSaiAnnadlfUrexoCtmeRnvtovuoecrfhieftirhesed,SbbayontttahheRouoarsustahaoBrnasds.aloTtnheiess
11We diinsctlaundte. the "Basalt of Elsinore Peak", oMuatlpinsehdowuisninggaltlhepoppruelsaetnitonsp.osiBt.ioEnxpoafndtehde-sBcaaslalet.maAp.
dated only as "Miocene" (Morton et al. 1999), as showing remaining areas covered by Santa Rosa Basalt
part of the Santa Rosa Basalt. Because these (black outline areas) and trails of the Santa Rosa
basalts most likely derived from the same or very Plateau Ecological Reserve in grassland (light gray).
similar source, and are from the same time
period, they are highly likely to be substantially
the same, and are treated as such here.
2007] CHESTER ET AL.: BRODIAEA SANTAROSAE 191
Fig. 2B shows the largest remaining areas of Key to the Species of Brodiaea in
the basalt, along with all vouchered locations Southern California
of B. santarosae and B. filifolia in that area.
Voucher locations of most B. santarosae speci- This key is an artificial key to separate all
mens are not precise; locations such as Mesa de species of Brodiaea in mainland southern Cali-
Burro have been arbitrarily placed on the Mesa. fornia. In this key and subsequently in this paper,
Most of the extant basalt is on the mesas of the the properties of the staminode refer only to its
Santa Rosa Plateau, not all of which have yet free portion and do not include the lower
been surveyed for these species. All Santa Rosa continuation of the staminode that is fused to
Basalt areas surveyed to date contain B. santa- the outer perianth.
rosae.
Perhaps the most remarkable feature of B. 1 Staminodes 0 in all flowers B. orcuttii
santarosae is that every population we surveyed 2V SSttaammiinnooddeess porbelsoenngt itno9r0e-ct1a0n0g%ulaorffilnowoeutrlsin.e.,. (2)
grows in soils derived from the Santa Rosa tapered only near tip ifat all (3)
Basalt. Every surveyed population except one, 2' Staminodesfiliform oruniformlytapered from
and all vouchers we determined as B. santarosae, base to tip (4)
were from soils underlain by the Santa Rosa 3 Staminodes generally erect, edges flat to
Basalt as mapped in Kennedy (1977). The inrolled, sometimes hooded, generally pur-
exception was the population immediately west ple B. terrestris ssp. l<ernensis
of the Mesa de Burro. Although the basement y Staminodes recurved, edges flat, not hooded,
rock there is mapped as metasedimentary, the soil pointed at tip, generally white; Mission Trails
had abundant basalt rocks within it and on its 4 RFeiglaimoennatlsP0a-r1k.5. m.Bm.;elsetgaamnsinHoodeosve1r.0su^b.s5p.memlegans
surface, remaining from the geologically-recent
past when the Santa Rosa Basalt was still intact 4" lFoinlga,mernetfslexe2d-8agmamin;stsptearmiainntohdes 0.0-7.0B.mfmilifolia
here. Thus this soil is derived, at least in part, long, recurved to erect (5)
from the basalt. 5 Perianth length 19-24 mm; style 8.0-9.5 mm;
This distribution thus shows tremendous fidel- ovary 4.0-5.0 mm; anther 5.0-5.5 mm; San
ity to the basalt areas, since both the populations Marcos B. filifolia X B. orcuttii
and the major remaining basalt areas (not 5' Perianth length 24-36 mm; style 10.5-
including the unsurveyed Oak Mountain) span 17.0 mm; ovary 3.5-8.2 mm; anther 5.4-
a distance of 15 km by 15 km, yet both B. 8.9 mm; Elsinore Peak to Miller Mountain
B. santarosae
santarosae and the basalt only cover almost the
-7%
identical (15 km2/225 km") ofthat area. Because onlythree specimens ofB. filifolia X B.
This coincidence is not due to habitat con- oreuttiiare known, therange ofmeasurements for
siderations; there are extensive grasslands inhab- it in the above keywill require slight extensions as
ited by B. terrestris Kellogg subsp. kernensis morespecimensarefound. However, theprincipal
(Hoover) T. Niehaus outside the basalt areas. No component analysis presented below indicates
other populations ofB. santarosae, B. filifolia, or that those extensions will be much smaller than
B. orcuttii have been documented even though the differences from B. santarosae.
those grasslands have been intensely studied. The
first and third author surveyed the grassland Phenetic Analysis of Brodiaea Santarosae
trails of the Santa Rosa Plateau Ecological and Other Brodiaea Species in
Reserve shown in Fig. 2B in 2001-2006; Lathrop Southern California
and Thorne (1985) surveyed most of the area
shown in Fig. 2B south of Murrieta; Boyd et al. Data and Analysis Methods
(1995) surveyed the rest of the area shown in
Fig. 2B; and there have been numerous surveys We surveyed, photographed, and sampled
for residential development. populations from the following areas, mapped
Thus, it is likely that there are no other in Fig. 2A, specifically forthis analysis, on 1,4, 5,
populations of B. santarosae other than those 10, 13, and 22 June 2006. The species determina-
shown, except for more populations in the basalt tion for each specimen was made later from the
areas themselves. In particular, Redonda Mesa analysis in this paper. Numbers in parentheses
and Mesa de la Punta may contain additional are collection numbers of Chester et al. B.
populations. In addition, therearea fewlocations filifolia: Santa Rosa Plateau Ecological Reserve
that have small remnants of the Santa Rosa (SRPER): Vernal Pool Trail near Main Pool
Basalt, not shown on the map, such as the (909); San Marcos (912); San Mateo Canyon
Murrieta Hogbacks and Oak Mountain. These Wilderness: Mud Canyon 1 (920, 933), Mud
areas should be searched for B. santarosae. It is Canyon 2 (924). B. filifolia X B. orcuttii: San
also possible that small populations of B. Marcos (917, 936). B. orcuttii: Miramar (915);
santarosae might occur in drainages from basalt Cuyamaca Lake (916); Tierra Santa (935). B.
areas, carried there by runoff. santarosae: SRPER: Clay Hill Area (910-911,
MADRONO
192 [Vol. 54
925-930), Via Volcano Road (921); Elsinore Peak
(918); Avenaloca Mesa (934). B. terrestris subsp.
kernensis: Elsinore Peak (919); SRPER: Via ^ A
E
Volcano Road (922). E
Mud Canyon is the informal name used for the 2
dArraeianagneearin DtehveilSanCaMnaytoenotChaatnycoonntWaiilnsderMneusds sa 0 B.santarosae
I-
Springs. Mud Canyon 1 isadrainagefroma fairly
large upstream meadow area. Mud Canyon 2 is
a small grassy area a few hundred feet south of
Mud Canyon 1. '"^ Bk.ertneernressitsrissubsp.
In each area, wephotographed the full range of
variation seen in the flowers, and we selected 5- -10 -5 0 5 10
10 inflorescences or flowers to measure in detail. PrincipalComponent1(mm)
The samples were selected mostly geographically,
from the edges ofeach area and from the center, pFiagr.ame3t.ersPrniontcispcaalledCboympsotnanednatrsd dAevniaaltyisoins. Tohfefmleoraanl
in order to avoid having multiple samples from values with their one-standard deviation error bars are
the same clonal population. {Brodiaeas often shown for the eleven geographically-distinct popula-
reproduce by corms, and hence the population tions given in Table 1. Rectangles delineate individual
in a small area is often clonal.) Samples were also taxa with more than one population; circles denote the
taken of extreme members of the population if mean for each taxon. To convert to PCA values from
tthhee gvearoigartaipohnicseseanmpilnintghedipdopnuoltatieonnc.omTphaessonalel fPlCorAall pbayra0m.e3t8e9rsmsmcal'edanbdysPtCaAnd2arbdyd0e.v4ia2t5iomn,mmultiply
exception to the above sampHng was on the 18
June 2006 visit to San Mateo Mud Canyon 1, give the otherversion are given in the caption for
where we intentionally sampled only the largest Fig. 3.
flowers from the B. filifolia population in an
attempt to discover any population intermediate Results ofAnalysis ofCharacteristics of the
to B. santarosae. (Later analysis showed no Brodiaea Species
intermediates were found.)
For comparison purposes, especially to study The coefficients of the first two principal
any possible hybridization, we also used data components (PCI and PC2) are given in Table 1,
collected in 2005 from the SRPER for fresh along with the variation in PC2 contributed by
samples ofB. terrestris subsp. kernensis. each variable. These two components accounted
Fourteen independent characteristics were for 89% ofthe total variance in the data.
measured for each fresh flower before pressing, Principal Component 1 is a length parameter,
in addition to the scape and bract length for each essentially a scale factor times the perianth length
inflorescence. In addition, all herbarium samples plus the portion of the length of the floral parts
of '"B. filifolid\ "'B. orcuttir\ and "B. filifolia X that is correlated to the perianth length. Principal
B. orcuttii'" from RSA and SD were examined Component 2 is essentially a scale factor times
and measured for all quantities visible on each the lengths of the filament plus the style minus
specimen, and re-determined. the perianth tube minus the perianth lobe minus
the staminode, where the staminode contributes
These characteristics were then analyzed di-
roughly twice the variation of the other param-
rectly and with principal components analysis.
eters. The variable staminodes of B. santarosae
Principal Components Analysis. The measure- account for most of the spread in values of PC2
ments of seven floral parameters (perianth lobe, for that taxon. Table 1 also shows the variation
perianth tube, filament, anther, ovary, style, and in PC2 contributed by each parameter.
staminode) were analyzed for principal compo-
nents, with the results separated by geographic Table 1. Coefficients for Principal Compo-
populations in Fig. 3. nents PCI AND PC2, AND Variation in PC2, By
We removed the mean from each floral Parameter.
parameter and then computed the principal
components in two ways, once dividing each Parameter PCI PC2 PC2 Variation (mm)
parameter by its standard deviation and once Tube 0.19 -0.36 -3.28
without such division. Since the resulting plots Lobe 0.70 -0.16 -3.46
were essentially identical except for scale Filament 0.36 0.46 3.73
(r-=0.95 for PCAl and 0.96 for PCA2), we Anther 0.18 0.02 0.11
present here the version without such scaling Ovary 0.21 -0.15 -1.00
which allows the coefficients to be more easily Style 0.51 0.22 2.94
Staminode 0.09 -0.76 -6.64
interpreted. The scale factors that will closely
2007] CHESTER ET AL.: BRODIAEA SANTAROSAE 193
The error bars in Fig. 3 were computed by the unusual rainfall pattern in 2006. For addi-
dividing the population standard deviation for tional detail, see Chester et al. (2007).
each species by (/z—1)'^-, where n is the number of
individuals in each population. Note that some Comparison of Individual Characteristics of
populations, such as B. filifolia and B. filifolia X Brodiaea Species in Southern California
B. orcuttii from San Marcos, are represented by
only three specimens, which accounts for some of Measured ranges for each parameter for each
the larger error bars. species are given in Table 2, along with the
Fig. 3 shows four distinct taxa that are nearly number ofsamples measured. We did not include
equally distant from each other, the three distinct B. elcgans or B. kiukiciisis in the analysis here
clusters denoted by labeled rectangles and the since they do not come into the geographic range
point corresponding to B. tevrcstris subsp. ofany southern California Brodiaea except for B.
kernensis. The B. filifolia X B. orcuttii specimens terrestris subsp. kernensis, and we thereforedidn't
plot almost exactly intermediately between the sample them for this analysis. (For this analysis,
parent species, as expected for Fl hybrids. Since we treat southern California specimens deter-
these specimens are found only in the single mined as B. jolonensis Eastw. as B. terrestris
location where the parent species occur together, subsp. kernensis. They have numerous differences
the evidence for their hybrid origin is strong. from specimens of B. jolonensis from the type
The separation of the taxa in Fig. 3 demon- locality ofJolon, CA, and are nearly identical to
strates that B. scmtarosae is a taxon as distinct as specimens of B. terrestris subsp. kernensis. The
)
any of the other three taxa, with characteristics sampling of B. terrestris subsp. kernensis was not
not intermediate to any of those three taxa. In extensive enough to give the full range for its
particular, these specimens are not direct hybrids parameters, especially from other locations.
ofB. filifolia and B. orcuttii, nor are they part of Brodiaea santarosae showed the following
any hybrid swarm between those species. Our substantial differences from B. filifolia and B.
discovery ofclear hybrids between B.filifolia and orcuttii:
B. orcuttii, from the only location where the
populations overlap, confirms these conclusions. (1) It had larger fiowers and larger fioral parts.
The clusters denoted by the labeled rectangles The median B. santarosae fiower was 40%
in Fig. 3 are robustly defined. Note in particular larger than the median B. filifolia and B.
the very small error bars on the PC2 values for all orcuttii fiower. Only a small percentage of
taxa except B. santarosae; within each of those B.filifolia and B. orcuttiifiowers were larger
clusters, all populations show extremely good than the smallest B. santarosae fiower.
concordance for PC2 in Fig. 3, reflecting the (2) The anther, ovary and style lengths of B.
uniform staminodes of each taxon. The popula- santarosae were all markedly longer than
tions of B. scmtarosae also show good concor- those for B. filifolia and B. orcuttii. There
dance, with each having significant spreads in the was almost no overlap at all for anther
values ofPC2, reflectingthe staminode variability lengths, and only a small overlap for the
of that species being consistent between popula- other lengths.
tions. (3) The inflorescence bract and pedicel lengths
For both PCI and PC2, the mean of each for B. scmtarosae were typically much
population is consistent with the corresponding longer than those of B. flifolia and B.
species mean (Fig. 3), except for the B. orcuttii orcuttii. Two-thirds ofthe bract lengths for
population with the highest value of PCI. That B. filifolia and B. orcuttii were shorter than
population (San Marcos) is 3.3 standard devia- 6 mm; none of the bracts of B. santarosae
tions away from the species mean value. Since were that short. All pedicels of B. filifolia
PCI is essentially the perianth length, this simply and B. orcuttii were shorter than 75 mm,
means that the San Marcos fiowers in our sample but over one third of the pedicels of B.
were significantly larger than the other two scmtarosae were longer than 75 mm.
populations from Miramar and Cuyamaca Lake. (4) The peduncle lengths for B. santarosaewere
Although the San Marcos specimens possessed also much longer than those of B. filifolia
somewhat-larger flowers, they are otherwise and B. orcuttii. However, this may simply
consistent with the other two B. orcuttii popula- be a consequence ofthe habitat difference.
tions in all respects. In particular, they have the B. santarosae grows in areas with abundant
distinctive properties of B. orcuttii described tall non-native grasses, whereas the other
below, including the complete absence of stami- two species grow in areas without as much
nodes. Herbarium specimens show a much smal- such cover.
ler separation of San Marcos fiowers from the
other two populations in other years, indicating In the rest ofthis section, we compare all four
that the apparent difference in our samples was species and give those properties in which one or
either sampling variation or perhaps related to more species significantly differed at close to or
MADRONO
194
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2007] CHESTER ET AL.; BRODIAEA SANTAROSAE 195
exceeding the 95% confidence level (with a differ-
ence more than two standard deviations). Plots, HistogramofPeduncleLengths
histograms, and additional information are given
in Chester et al. (2007).
Habitat. The habitats of the four species are
distinct. B.filifolia and B. orciittii are confined to B.f.
the wettest areas such as flat streambeds, benches aBs.o..
along streambeds, and vernal pool areas. B. B.t.k.
terrestris subsp. keniensis and B. santarosae are
less moisture-dependent. B. terrestris subsp.
keniensis grows in many habitats, but generally
does not occur in thewettest areas preferred by B. 100 200 300 400
filifolia and B. orcuttii. It grows in drierdrainages Pedunclelength(mm)
and along trails and roads in flattish areas.
Brodiaea santarosae grows in many habitats as
well, including next to vernal pools, but can grow HistogramofBractLengths
in drier locations than even B. terrestris subsp.
kernensis. Surprisingly, B. santarosae even grows
in disturbed areas such as Waterline Road next to
the Mesa de Burro. That area wascompletely dug
up to install a water main, and B. santarosae B.f.
^-B.o.
grows abundantly in the disturbed soil on top of -^B.s.
the water pipe, as well as in roadside berms. B.t.k.
There is only one known occurrence of B.
filifolia within the range of B. santarosae, on the
Mesa de Colorado immediately surrounding the
largest vernal pool. The area in which it grows 5 10
was part of that pool for —75 years, when the Bractlength(mm)
outlet ofthe pool was dammed to raise the level
of the pool. The soil in that area is heavily
leached, and does not have the red color of the HistogramofPedicelLengths
surrounding basalt-derived soil. B. santarosae is
not found on that vernal pool soil, only in the red
basalt soil elsewhere on the Mesa de Colorado.
Of course, the most remarkable difference in
habitat is the restriction ofB. santarosae to basalt BB..fo..
soil in areas on or near the Santa Rosa Basalt. as.
B.t.k.
Peduncleandbract lengths. Histograms ofthese
two parameters (Fig. 4) each showed two distinct
patterns: B. filifolia and B. orcuttii had similar
histograms that peak at shorter values, and B. 40 60 80 100 120
santarosae and B. terrestris subsp. kernensis had Pedicellength(mm)
similarhistograms that peakat longervalues. For
example, 60% ofthe peduncles for B. filif)lia and Fig. 4. Histograms of peduncle, bract and pedicel
B. orcuttii were less than 150 mm, but only 27% lengthsfor B.filifolia (B.f), B. orcuttii (B.o.), B. santa-
of the peduncles for the other two species were rosae (B.S.). and B. terrestris ssp. kernensis (B.t.k.).
that short. Even more dramatically, 65% of the
bract lengths for B. filifolia and B. orcuttii were
less than 6 mm, but none ofthe bract lengths for orcuttii are found in habitats that largely exclude
the other two species were that short. non-native annual grasses, whereas B. terrestris
Although it is possible that the peduncle length subsp. kernensis and especially B. santarosae are
further distinguishes B. santarosae from B. found in drier habitats that favor those grasses.
filifolia and B. orcuttii, we suspect the peduncle Supporting our suspicion, the range ofpeduncles
length is subject to environmental modification is essentially the same for every species even
by the height of the immediately-neighboring though the histograms are different, implying
plants, which in turn derives from the different that each species grows its peduncle long enough
habitats of these species. Peduncles are shorter for its flowers to be out in the open.
where there are few neighboring plants, and The difference in bracts is more fundamental
longer where the plant is surrounded by tall since the range for bract lengths is very different
annual non-nativegrasses. Both B. filifolia and B. among the species; there seems to be a firm upper
MADRONO
196 [Vol. 54
Table 3. Scalingof Floral Characteristicswith Perianth Length: Slopeand Standard Deviation.
Slope values in bold type indicate characteristics significantly larger than for the other species; values in italics
indicate significantly-smaller characteristics.
B. tervestris subsp.
Characteristic B. filifolia B. orcuttii B. sciutarosae kernensis
Perianth tube 0.20 0.04 0.31 0.05 0.05 0.07 0.28 0.07
Perianth lobes 0.80 -H 0.04 0.69 0.05 0.95 -1- 0.07 0.72 0.07
Filament 0.09 0.02 0.19 0.03 0.26 -H 0.09 0.11 0.06
Anther 0.13 -H 0.03 0.13 0.02 0.17 H- 0.04 0.16 -H 0.03
Ovary 0.19 -H 0.04 0.19 0.03 -0.01 -1- 0.06 0.14 -+- 0.07
Style + stigma 0.31 0.05 0.41 0.05 0.37 0.06 0.17 -H 0.04
Staminodes (free portion) 0.04 -H 0.03 0.00 0.00 -0.19 + 0.14 0.16 0.07
limit for the bract length of B. filifolia and B. The scaling with perianth length for the other
orcuttii. floral parameters, given in Table 3, was generally
consistent between all species, with the following
Pedicel lengths. As for the peduncle and bract exceptions: the tube for B. filifolia grew more
lengths, B. filifolia and B. orcuttii had a similar slowly with perianth length than did the tube for
patternwithhistogramsthatpeakatshortervalues B. orcuttii, a difference of 1.7 standard deviations
(Fig. 4). However, B. terrestris subsp. kernensis (P = 0.09 due to chance); the filament length for
had a histogram shifted only sHghtly to larger B.filifolia grew more slowly with perianth length
values, whereas B. santarosae had a histogram than did the filament lengths for B. orcuttiiand B.
shifteddramaticallytolargervalues. Forexample, santarosae, differences of2.9 standard deviations ,
all pedicels ofB. filifolia and B. orcuttii were less (P = 0.004) and 1.9 standard deviations (P = !
stahnatnaro6s0aem,ma,ndb1u3t%3o7f%theopfedtihceelspeodfiBc.eltserroefstrBi.s 0s.t0i6g)m,a)rlesepnegctthivfeolry;B.atnedrrestthreis sstuyblsep.(iknecrlnuednisnigs Ij
subsp. kernensis, were greater than 60 mm. grew more slowly with perianth length than did
Floral parameter lengths. Analysis of seven the styles for the other species, differences of2.1-
floral parameters, plotted against perianth length 3.9 standard deviations (P = 0.04-0.0001).
and analyzed with linear regression, revealed that Table 4 gives the mean values and standard
every floral parameter for every species scaled deviation ofthe mean for the floral characteristics.
with the perianth length with two exceptions. Significantly-larger mean values are in bold type;
First, the staminodes for every species except B. significantly-smaller values are in italics; the
terrestris subsp. kernensis did not scale with differences here range from 4.4-10 standard devia-
perianth length. The staminodes for B. terrestris tions (P<10"'^). Six of the seven characteristics of
subsp. kernensis scaled with perianth length much B. filifolia and B. orcuttii were significantly-
the same as every other non-corolla floral smaller than at least one ofthe other two species; ;
parameter, which had slopes of 0.11 to 0.17. in contrast, six of the seven characteristics of B.
(This slope value means that for every 10 mm santcu'osae were significantly-larger than at least
enlargement ofthe corolla, the other part length- one of the other two species. Interestingly, B. ,
espnescibeys1.h1atdo 1f.i7ttmedmsloonpeasvercaognes.i)stAelnltofwitthehoztehreor stemrarlelsetrrivsasluubesspa.nkderfnoeunrssiisgnhiafdictahntrleye-lsairggneirfivcaalnutelsy.- ;\
within two standard deviations. (The slope was of In addition, thewidth ofthe antheraxis tmissmue for
csotuarmsienodeexalcetnlgythziesraolwfaoyrs zBe.ro.o)rcTuhtteiifitstiendcseloiptes Bn.evteerrrbeestcraismesuabsspn.arkreronwenassitshweamsin0.i5m-0u.m9valueafnodr i
of the staminode length for B. santarosae was each the other species of0.2 mm. j
;
actually negative with perianth length; i.e., there 1
was a tendency for the maximum staminode Conclusions and Discussion '
length to decrease with increasing perianth
length. However, the slope value was only 1.4 Brodiaea santarosae merits designation at the
times its standard deviation, consistent with zero. rank of species. The plants are taxonomically
Second, the perianth tube and ovary length for distinct in a number of significant features from j
B. santarosae did not scale with perianth length. all other Brodiaea species, and in fact are among
It is tempting to say that these values have simply the most distinctive Brodiaea species. The plants
reached their maximum values for the large are not direct hybrids of B. filifolia and B.
flowers of this species, but both characteristics orcuttii, nor are they part of a hybrid swarm
had a significant positive slope for B. terrestris between those species. The plants form a homo-
subsp. kernensis, which had equally large flowers. geneous population with a well-defined geo-
These two exceptional traits add to the suite of graphic range. Further, as is often the case for i
characters that make B. santarosae distinctive. many recently-recognized species, this species is