151 Figure 51
Cornus Stockii n. sp.
Four stones (seeds) of a number found in matrix from Pit A; no depth was given.
(Scale: 1 square in grid = 1 sq. mm.)
Figure 52
Cornus stolonifera Michx.
Two stones (seeds) of the modern species; one shows the grooved end and the other one a view of the smooth side; for comparison with the fossil seeds shown in Figure 51.
(Scale: 1 square in grid = 1 sq, mm. ) 152 153
Collection: Los Angeles County Museum, Paleobotany,
Type No. PB. 1445.
ERICACEAE Family
Arctostaphylos
There are approximately 50 species of Arctostaphylos in North and Central America, distributed mainly on the Pacific Coast. One
species, Arctostaphylos uva-ursi, has circumpolar distribution.
About 43 species and several varieties as well as natural hybrids oc- cur in the California flora. More than 50% of these occur in the chaparral on the foothills of the Coast Ranges and the Sierra Nevada
Mountains; about 15 percent occur in open forest areas, 5 percent on the Coastal Islands of southern California, and about 20 percent occur in moist places or sand hills and bluffs along the immediate coast.
The identification of the species of Arctostaphylos is rather difficult. Some use has been made of the berry- or drupe-like fruits as a means of identification, and whether the stony nutlets are se- parable, or variously coalesced. However, very little attention has been given to the external morphology of the stony nutlets.
A number of stony nutlets, some variously or wholly coalesced, were found in several pits of the Rancho La Brea deposits. Since none of these stony nutlets were enclosed in fleshy exocarp nor at- tached to the herbaceous Arctostaphylos material essential for 154
identification, it was necessary to study the nutlets of species of
Arctostaphylos that occur now, or may have occurred during Pleis-
tocene times in this area. The stony nutlets of the following species were studied and compared with the fossil specimens:
Arctostaphylos auriculata Arctostaphylos glauca Arctostaphylos canescens Arctostaphylos Hookeri Arctostaphylos columiana Arctostaphylos insularis Arctostaphylos glandulosa Arctostaphylos manzanita Arctostaphylos morroensis Arctostaphylos stanfordiana Arctostaphylos pajaroensis Arctostaphylos subcordata Arctostaphylos patula Arctostaphylos tomentosa Arctostaphylos pechoensis Arctostaphylos uva-ursi Arctostaphylos pungens Arctostaphylos viscida Arctostaphylos Pringlei Arctostaphylos Parryana
Varieties of several of the above species were also studied. In addi- tion, the stones of two other species that have formerly been placed
in the genus Arctostaphylos but now classified under Comarostaphylos
and Xylococcus were also studied.
A number of berries of each species was soaked in hot water
in order to remove the hard, dried pulp. The pulp was carefully re- moved to observe the form and condition of the endocarp; whether the nutlets formed a solidly coalesced stone, or whether all nutlets were free from each other, or partly free and partly coalesced. As
some of the fossil nutlets had a distinctive rugose pattern on the dorsal face and even on the normally coalescent surfaces, particular attention was given to these patterns and the forms of the individual nutlets in each species. 155
From this study of the fruits, it was possible, with some reser- vations, to arrive at a fairly accurate identification of the fossil ma- terial. Much more material should be studied of each species in or- der to be certain of the identifications. Until this can be done, there must be some doubt of the identifications in some instances.
Arctostaphylos insularis Greene
One almost complete stone was extracted from the matrix in
Pit 4. The stone is somewhat flattened and has one or possibly two nutlets missing; it is about 7 mm. in diameter, and 5 mm. high, bears several vertical ridges;between these there are pronounced rugose markings (Figure 53).
The modern species occurs in chaparral on Santa Cruz and
Santa Rosa Islands (Map 10) and has fruits 6-8 mm. broad with the nutlets irregularly coalescent and ridged on the back (Figure 54).
Occurrence: Rancho La Brea deposits, Pit 4, Sect. F-4.
Collection: Los Angeles County Museum, Paleobotany,
Plesiotype, No. PB. 1497.
Arctostaphylos morroensis Wies. and Schreib.
Several nutlets, that are comparable with this species occurred in Pit 101. The nutlets (Figure 55) are broadly wedge-shaped, with
2-3 ridges on the dorsal face and faintly rugose between the ridges and partly down the coalescing face. They are 4-5 mm. wide and 1 5 6
MAP OF CALIFORNIA
• ARCTUSTAPHYLOS INSULARIS Greene 0 ARCTOSTAPHYLOS NORMANS S mot,: Wies. Schreib.
The distribution of these species is
shown here. They were mapped from data of field collections in herbaria. It
will be noted that these occur in the flora today in localities far remote to the site of deposition.
-010" Rancho La Brea deposits
■ 157 Figure 53
Arctostaphylos insularis Greene
Fossil stone from matrix in Pit 4, Sect. F-4 at 15 feet.
a. Side view. b. Top view. c. Bottom view.
(Scale: 1 square in grid = 1 sq, mm. )
Figure 54
Arctostaphylos insularis Greene
Modern stone of the species shown here for comparison. a. Top view. b. Bottom view.
(Scale: 1 square in grid = 1 sq. mm. ) 158
Figure 55 Arctostaphylos morroensis Wies. and Schreib.
Fossil nutlet extracted from matrix in Pit 101.
a. Dorsal and side view of nutlet. b. Reverse view of nutlet.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 56
Arctostaphylos morroensis Wies. and Schreib.
Modern nutlets shown here for comparison. a. Shows form of two nutlets. b. A nutlet from another stone.
(Scale: 1 square in grid = 1 sq. mm. ) 160 161 about 3 mm. high indicating that they came from a berry having a stone approximately 8-10 mm. in diameter, considerably compressed and with separate nutlets.
The modern species occurs in chaparral on sandy hills south of
Morro Bay, San Luis Obispo County (Map 10). The fruit are slightly depressed-globose, about 10 mm. in diameter with nutlets separating
(Figure 56, p. 159).
Occurrence: Rancho La Brea deposits, Pit 101.
Collection: Los Angeles County Museum, Paleobotany,
Plesiotype No. P13. 1498.
Arctostaphylos pechoensis Dudl. ex Abrams
Several nutlets, which appear to resemble this species, were extracted from matrix in Pit 13. These are somewhat wedge-shaped,
3 mm. broad on the adhering face, 5 mm. high at the axis edge, and about 2 mm. thick at the dorsal face; no rugose surface apparent
(Figure 57).
These thin wedge-shaped nutlets may appear to resemble closely the nutlets of some other species, but the one distinguishing feature that made it possible to assign these fossils to A. pechoensis is the broad, smooth, flat face of its adhering side which extends from its axis-edge to almost the very edge of its dorsal face, and the lack of pitted rugose surface on the dorsal edge. 162 Figure 57 Arctostaphylos pechoensis Dudl. ex Abrams
Fossil nutlet extracted from matrix removed from inside of sabre-tooth cat skull in Pit 13, Sect. F-11, 111 ft.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 58
Arctostaphylos pechoensis Dudl. ex Abrams
Several nutlets of this species shown here for comparison. Side Views.
(Scale: 1 square in grid = 1 sq. mm.) 163 164
The modern species occurs in chaparral on slopes and ridges
from west central San Luis Obispo County south to northern Santa
Barbara County (Map 11), has depressed-globose fruit 8-10 mm. in
diameter and nutlets irregularly separable. A number of berries of
this species examined were found to have at least two or three wedge-
shaped nutlets (Figure 58, p. 163) that appeared exactly like the fos-
sils.
Occurrence: Rancho La Brea deposits, Pit 13.
Collection: Los Angeles County Museum, Paleobotany,
Plesiotype No. PB. 1499.
Arctostaphylos tomentosa (Pursh) Lindl.
One complete, carbonized stone (Figure 59) resembling those of the modern species occurred in the matrix from inside a sabre- tooth skull in Pit 67. It is broadly ovate with a bluntly acuminate apex and is 7 mm. wide at its broadest point and 7 mm. high.
The fruit of the modern species is described as being depressed- globose, 8-10 mm. across, the nutlets irregularly coalescent and wrinkled on back. A number of berries were examined, some are depressed-globose but the stones within possess various forms and segment into a variety of forms. Invariably 1/3 to 2/3 of the nutlets remain coalesced and many of these (Figure 60) possess forms like that of the fossil. 165
MAP OF CALIFORNIA
ARCTOSTAPHYLOS PECHOENSIS Dudl. ex Abrams
The distribution of this species, mapped from data of field collec- tions in herbaria, is a limited one. Its nearest locality to the deposits is that on Santa Catalina Island.
"ob ■ 166 Figure 59 Arctostaphylos tomentosa (Pursh) Lindl
A complete carbonized stone extracted from matrix inside of sabre-tooth cat skull in Pit 67, Sect. G-7, 17 1 - 18 -i1• ft.
(Scale: 1 square in grid = 1 sq, mm.)
Figure 60
Arctostaphylos tomentosa (Pursh) Lindl.
A partial stone of the modern species shown for comparison.
(Scale: 1 square in grid = 1 sq. mm. ) 167 168
Arctostaphylos tomentosa, in the modern flora of California, occurs in chaparral and the closed-cone Pine forest about Monterey
Peninsula south to north San Luis Obispo County. From studies of specimens of herbaria, however, it appears that this species occurs beyond this range (Map 12).
Occurrence: Rancho La Brea deposits, Pit 67, Sect.
G-7, at 17 2 to 18 i feet depth.
Collection: Los Angeles County Museum, Paleo-
botany, Plesiotype No. PB, 1500.
Arctostaphylos viscida Parry
Several nutlets resembling this species were found in Pit 3.
Each is a thin, broadly wedge-shaped crescent 3 mm. high at its ventral edge and 3 mm. broad, indicating that the stone from which it came was approximately 6 mm. in diameter and 3 mm. high, of depressed globose form; the adhering face is a small crescent about
1.5 mm. at its widest part, smooth, the remaining surface of the sides of the nutlet is rugose-pitted, and has a keel or ridge on its narrow dorsal face (Figure 61).
The fruit of the modern Arctostaphylos viscida is a depressed globe, 6-8 mm. broad, the nutlets usually separable, angled and roughened on back. In a number of berries examined, every stone separated into nutlets with as many as three and four nutlets having 1 69
NAP OF CALIFORNIA
.RCTuSTAPHYLOS TOMBNTOSA (Pursh) Lindl.
The distribution of this species, map- ped from data of field collections in herbaria, appears to be in widely dis- junct areas. The nearest locality to the deposits is than on Wilson's Peak, San Gabriel Mountains.
•
wj a a
Rancho La Brea deposits
Figure 61
Arctostaphylos viscida Parry
Fossil nutlet extracted from matrix inside of sabre-tooth cat skull in Pit 3 at depth of 4 feet.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 62
Arctostaphylos viscida Parry
Several nutlets of the modern species shown for comparison,
(Scale: 1 square in grid = 1 sq, mm, ) 171
•
t _ irram+ripm-'1a-rms.:- Am*
%pop rprrtraTt--.max. r
r--1--- -,...„. 1/4... .,,..__.. I1' . q • 172
a form (Figure 62) very nearly like those of the fossils.
This species occurs on slopes and foothills of the Sierra Nevada
from Kern County north, and in the North Coast Ranges from Lake
and Napa Counties north to Oregon. Map 13 shows the distribution
based on data from field collections studied in herbaria.
Occurrence: Rancho La Brea deposits, Pit 3, at a
depth of four feet.
Collection: Los Angeles County Museum, Paleobotany,
Plesiotype No. PB. 1501.
Xylococcus bicolor Nutt.
A part of a stone, considerably worn, occurred in the matrix
from inside a sabre-tooth skull excavated from Pit 13. It is nearly
5 mm. across and 4 mm. high and is composed of five regularly
formed, coalesced nutlets (Figure 63). Although it is slightly small- er than the modern nutlet of Xylococcus bicolor (Figure 64) it appears to resemble this species almost exactly.
Xylococcus bicolor occurs in the chaparral at scattered locali- ties along the coast from Los Angeles County south to Lower Califor- nia. Map 14 shows its distribution as determined from studies of records in herbaria.
Occurrence: Rancho La Brea deposit, pit 13, Sect.
F-11 at depth of 11 i feet. 173
MAP uF CALIFORNIA
ARCTUSTAPHYLOS VISCIpA 1 arry
The ralve of this species, :-;_need
tro: data of field collections in
herbaria, occurs plainly on toot-
hills alor7 the western slope of
the Sierra Nevada :. buntains and far
remote to the Rancto La Brea de-
posits.
Rancho La Brea deposit 174 Figure 63 Xylococcus bicolor Nutt.
Fossil stone showing coalescent nutlets extracted from matrix in- side sabre-tooth cat skull in Pit 13, Sect. F-11, at depth of 111 feet.
(Scale: 1 square in grid = 1 sq. mm.)
Figure 64
Xylococcus bicolor Nutt.
A stone of the modern species shown here for comparison.
(Scale: 1 square in grid = 1 sq. mm.)
175
11 Il 1, , •. s „ _...... _ . . ti 1 1!. il Ii II J._._..ji:. i .11...._1 l-i 1 P r
V. 11 L •
II. il 11 I,j. 11 II ii --- ii 11 )1/1 't II I 1
)! I i' A I, 1,. ii 1 II li il I ..e. II it- 1Itl.1 it t !Ili , II ii 1 11 I ii _....L.,....:.. . = ... _ II II li lil 11 III 111'. 11 I 1 ) /
I _i -iii [ I 11 I _ I II il II 11 1.1 I 176
MAP OF CALIFORNIA
Map 14.
XYLOCUCCUS BICOLOR Nutt.
Tile distribution of this species, map-
red from studies of field collections
in herbaria, appears to occur in a s m all area in the Verdugo Range, Los
Angeles Co. and then in San Diego Co.
125 riles to the south of the deposits.
The Santa Monica Mts., north of the de- posits,limits tie species grow- 44. ing in the Verdugo Range from \41 entering into the area of de-
position today.
Rancho La Bret deposits 177
Collection: Los Angeles County Museum, Paleobotany,
Plesiotype No. PB. 1502.
SCROPHULARIACEAE Family
Antirrhinum L.
Fossil seeds and a capsule, resembling those of Antirrhinum were extracted from matrices in several pits. A number of modern
species had seeds that appeared to be very similar. The following
species were studied and compared with the fossils:
Antirrhinum Breweri Antirrhinum Nuttallianum Antirrhinum cornutum Antirrhinum Nuttallianum Antirrhinum Coulterianum var. pusillum Antirrhinum Coulterianum Antirrhinum ovatum var. Orcuttianum Antirrhinum speciosum Antirrhinum cyathiferum Antirrhinum subcordatum Antirrhinum filipes Antirrhinum vexillo- Antirrhinum glandulosum calyculatum Antirrhinum Kelloggii Antirrhinum virga Antirrhinum Kingii Antirrhinum Watsonii
The fossil seeds were found to resemble almost exactly those of
Antirrhinum Nuttallianum Benth. The capsule also, although worn and fragmented, appeared to resemble very closely those of this spe- cies.
Antirrhinum Nuttallianum Benth.
Antirrhinum Nuttallianum is represented in the deposit by one capsule and several seeds (Figure 65). The capsule is badly mas- cerated, the portion above the distal pores including the persistent 178 Figure 65 Antirrhinum Nuttallianum Benth.
Fossil seeds and a capsule extracted from matrix in Pit A. a. Four seeds. 15 x b. One seed, magnified 50 x. c. Capsule, side view.
(Scale: 1 square in grid = 1 sq. )
Figure 66
Antirrhinum Nuttallianum Benth.
Modern seeds and a capsule shown here for comparison.
a. Three seeds. b. Capsule, side view.
(Scale: 1 square in grid = 1 sq. mm. ) 179 180
style is missing. The modern capsule (Figure 66, p. 179) is asym- metrical, oblique or pouched at base, about 6 mm. long and 4 mm. wide, exclusive of peduncle and style. The fossil capsule is 4 mm. long from base of pouch to the broken top. The fossil seeds resemble the modern seeds (Figure 66). They are oblong, 0.75 mm. long, 0.50 mm. wide, subcylindrical, with more or less parallel cristate- costate ridges.
The modern counterpart occurs in sandy or rocky soil of rather dry situations below 2, 000 feet. Its range (Map 15) is near the coast from Santa Barbara County to San Diego County, southward into northern Lower California; Santa Cruz, Santa Catalina, San Clemente, and Coronado Islands. This species inhabits areas very near the ocean, scarcely extending more than 15 to 20 miles inland; only two collections have been made farther inland in southern California, one in the San Gabriel Mountains and one in the San Bernardino Mountains.
The nearest modern record to the fossil deposit is that at Playa del
Rey, about 20 miles west of Rancho La Brea.
Occurrence: Rancho La Brea deposits, Pit A; no
section or depth given;
Collection: Los Angeles County Museum, Paleo-
botany, Plesiotype Nos. PB. 1438 and
PB. 1439. 181
MAP OF CALIFORNIA
ANTIRRHINUM NUTTALLIANUM Benth
Tie range of this species is given as occurring along the coast from Santa Barbara to San Diego Counties, on the coastal Islands, California, thence southward into northern Lower Califor- nia. The distribution shown here, how- ever, was mapped from studies of field collections in herbaria. These A. did not show it occurring in Santa Barbara or Ventura Coun- ties proper. Note \\' also, that it does not occurr near the ) deposits today. '\
e1/4,
21. 4t".
Rancho La Brea deposits/46 182
Orthocarpus Nutt.
Two seeds closely resembling those of Orthocarpus were separ- ated from matrix from the Rancho La Brea deposits.
The seeds of the modern Orthocarpus and Castilleja have a more or less loose reticulate or alveolate coat. The seeds of species of these two genera were studied to determine the relationship of the fossil specimens. Those of Castilleja possess coats that appear more opaque, the reticulate fibers coarser, and are generally larger than those of Orthocarpus. Those of Orthocarpus more nearly re- semble the fossils.
There are about 24 species of Orthocarpus in the modern flora of California. These species may be divided into two groups. In one group the seed possesses a close coat, the other a loose cellular coat.
Since the fossil seeds have a loose cellular coat, the species possess- ing close coats were eliminated from consideration. The following species were studied:
Orthocarpus attenuatus Orthocarpus luteus Orthocarpus densiflorus Orthocarpus pilosus Orthocarpus faucibarbatus Orthocarpus purpurascens Orthocarpus imbricatus Orthocarpus tenuifolius
The fossil specimens more nearly resemble those of Orthocarpus purpurascens than any of the other species. 183
Orthocarpus purpurascens Benth.
One seed, complete with loose-fitting coat and one fragmented seed coat without a seed occurred in matrix from Pits 61 and 67.
These pits were adjoining in the excavations.
The hyaline tissue is missing and only the fibers of the seed coat remain; likewise, the hyaline tissue is missing in the fragment- ed seed coat. The complete seed (Figure 67) has a loose-fitting coat that is ovate 1 mm. wide and 1.5 mm. long. This resembles many of the modern seeds (Figure 68). The seed within is ovoid, about
0.5 mm. long. This is about half the size of the modern seed (1 mm.) and may be due to shrinkage during fossilization.
Orthocarpus purpurascens occurs, in California, in open fields and grassy slopes below 3,000 feet in the San Joaquin Valley and to the coast, from Mendocino County south to Lower California, Map
16 shows the distribution of this species in southern California as determined from data of collections in herbaria. These plants are able to germinate, grow, bloom, and set fruit before the dry season begins.
Occurrence: Rancho La Brea deposits, Pit 67, Sect. ------C-8, at depth of 16 feet; Pit 61, at depth
of ten feet.
Collection: Los Angeles County Museum, Paleobotany, Plesiotype Nos. PB. 1503 and PB, 1504,
Figure 67 Orthocarpus purpurascens Benth.
Fossil seeds excavated from Pit 61 and Pit 67.
(Scale: 1 square in grid = 1 sq, mm. )
Figure 68
Orthocarpus purpurascens Benth.
Modern seeds of this species from two localities, shown here for comparison with the fossils. a, Seeds from plants in Madera County, California. b. Seeds from plants in Fresno County, California.
(Scale: 1 square in grid = 1 sq. mm.) 185 186
MAP OF CALIFORNIA
Map 16.
ORTHOCARPUS PURPURASCHNS Beath.
This species occurs in the Great Valley (San Joaquin), then west to the coast at Mendocino County, southward to Low- er California. Only species occurring in southern California, based on studies of field collections, has been mapped to show its abundance and approximity to the Rancho La Brea deposits.
•Z.1•54 187
ROSACEAE Family
A much worn and somewhat compressed seed that appeared to
be from Potentilla or Rubus occurred in the deposits. After a sur-
vey of several genera of Rosaceae, the seed seemed to approach
those of Rubus in morphological details and form and differed in
size and other characters from those of Potentilla.
Rubus L.
There are about five species of Rubus, exclusive of escaped
garden forms, in California. These are: Rubus leucodermis, R.
parviflorus, R. spectabilis, R. ursinus, and R. vitifolius. The
fruits and seeds of these species were studied and the fossil seed was found to resemble very closely those of Rubus vitifolius.
Rubus vitifolius Cham. and Schlecht.
The fossil seed occurred in Pit 3 and was extracted from ma- trix removed from inside of a sabre-tooth cat skull. The seed
(Figure 69) is oblique, almost 2 mm. broad and 2.5 mm. long; al- though the seed is considerably worn, and the reticulate pattern so evident in the modern seed (Figure 70) is gone, the somewhat para- llel crescent ridges, seen in the modern seed, are still present.
Rubus vitifolius occurs in woods and damp places below 4,000 feet, along the coast from Mendocino County to San Luis Obispo 188
Figure 69 Rebus vitifolius Cham. & Schlecht
A single fossil seed extracted from matrix removed from inside of skull of sabre-tooth cat excavated from Pit 3, Sect. F-2, at a depth of 15 z feet. (Scale: 1 square in grid = 1 sq. mm.)
Figure 70
Rubus vitifolius Cham. & Schlecht
A modern seed of this species shown here for comparison.
(Scale: 1 square in grid = 1 sq. mm.) 18 9
County, the foothills of the Sierra Nevadas and the foothills of moun- tains in southern California. Map 17 shows the distribution of Rubus vitifolius based upon studies of field collections in herbaria.
Occurrence: Rancho La Brea deposits, Pit 3, Sect.
F-2, at depth of 151 feet.
Collection: Los Angeles County Museum, Paleo-
botany, Plesiotype No. PB. 1505.
ANACARDIACEAE Family
This family is represented by one genus, Rhus, containing five species in the flora of California. All of the species occur in south- ern California. The fruits and seeds of the following species were studied and compared with the fossil material:
Rhus diversiloba Rhus ovata Rhus integrifolia Rhus trilobata Rhus laurina
The seeds of all of the species showed a slightly asymmetrical form.
The seeds of Rhus laurina are considerably smaller than the others.
The rugose markings on the face of R. diversiloba seeds distinguish it from the other California species. Since some question has oc- curred as to the relationship and synonymy of R. diversiloba and R. toxicodendron, the seeds of the latter species were also studied.
Instead of the smooth surface evident in seeds of most of the species of Rhus, the seeds of R. toxicodendron, like those of R. diversiloba, 19 0
MAP OF CALIFORNIA
The distribution of this sp ecies, shown
here, is based on data of field collec- tions in herbaria. Note that its near-
est locality to the fossil deposits
is a few miles to the west.
••• 191 have an irregularly rugose surface. A detailed account of the fruits and seeds of Rhus will be presented in another study.
Rhus diversiloba
Several seeds closely resembling this species have been taken from the matrix in two pits. The seeds (Figure 71) are devoid of the soft exocarp but the remaining hard endocarps with their peculiar rugose surfaces resemble in detail the structure of the modern counterpart (Figure 72).
Rhus diversiloba is a widely distributed shrub in modern Cali- fornia, inhabiting mountain slopes below 5,000 feet, valleys, foot- hills, and stream banks throughout the Coast Ranges, the Sierra
Nevada, and wooded slopes in southern California. It occurs more abundantly along borders of streams and in moist humid canyons than elsewhere. Map 18 shows the distribution of this species in southern California, based on collections in herbaria. This does not reveal its actual distribution because the dermatitis caused by this plant discourages collectors.
Occurrence: Rancho La Brea deposits, Pit 3, Sect.
F-2, in matrix from skull of sabre-
tooth cat, at depth of 151 feet.
Collection: Los Angeles County Museum, Paleo-
botany, Plesiotype No. PB. 1506. 192 Figure 71
Rhus diversiloba T. and G.
Fossil seed extracted from matrix re- moved from inside skull of sabre-tooth cat in Pit 3, Sect. F-2, at depth of 151 feet. a. Side view. b. View of reverse side.
(Scale: 1 square in grid = 1 sq, mm. )
Figure 72
Rhus diversiloba T. and G.
View of several modern seeds with both surfaces illustrated for compari- son with the fossil specimen.
(Scale: 1 square in grid = 1 sq. mm. ) 193 1 9 4
MAP OF CALIFORNIA
Map 18.
DIVISILUSA T. F:
distribution at t)1.710 sPecies, base,'1
on titn.lir•.s of ii2ld collections i;1 her-
baria, [,,ears to be in two vilely
senz-rated ar,, as. This does not, how-
ever, reveal its actual distribution be-
cause, due to dernatitis, caused by this
plant, it is not frequently collected.
Note that it occurs within ra.nre
or the aancho La I L ren deposits. 195
RUBIACEAE Family
Galium L.
A number of fruits that are identifiable with the modern fruits
of Galium were extracted from the matrix from several pits. These
are very black and have the wrinkled surface characteristic of their
modern counterparts.
There are approximately 38 species of Galium in the modern flora of California. From a precursory study of the fruits of these
species it appeared that a specific identification would be difficult.
However, some fruits have hairs and some are glabrous, which gave one means of limiting the number of species to be considered, Us- ing this character eliminated 28 species. Weedy introduced species were eliminated from comparison. There remained the following species for consideration: Galium Andrewsii, G. Bolanderi, G. cymosum, G. Nuttallii, G. sparsiflorum, and G. trifidum.
When the fossil fruits were compared with the fruits of these six species, they appeared to be nearest to Galium Nuttallii (Figure
73) and Galium trifidum (Figure 74). The fruits of Galium Nuttallii are 2-3 mm. in diameter and generally much larger than the fossils, while those of Galium trifidum are 1-1.5 mm. in diameter approach- ing most of the fossil fruits in size. 195
RUBIACEAE Family
Galium L.
A number of fruits that are identifiable with the modern fruits of Galium were extracted from the matrix from several pits. These are very black and have the wrinkled surface characteristic of their modern counterparts.
There are approximately 38 species of Galium in the modern flora of California. From a precursory study of the fruits of these species it appeared that a specific identification would be difficult.
However, some fruits have hairs and some are glabrous, which gave one means of limiting the number of species to be considered. Us- ing this character eliminated 28 species. Weedy introduced species were eliminated from comparison. There remained the following species for consideration: Galium Andrewsii, G. Bolanderi, G. cymosum, G. Nuttallii, G. sparsiflorum, and G. trifidum,
When the fossil fruits were compared with the fruits of these six species, they appeared to be nearest to Galium Nuttallii (Figure
73) and Galium trifidum (Figure 74). The fruits of Galium Nuttallii are 2-3 mm. in diameter and generally much larger than the fossils, while those of Galium trifidum are 1-1.5 mm. in diameter approach- ing most of the fossil fruits in size. 196
Figure 73 Galium Nuttallii Gray
Fruit of the modern species used for com- parison with the fossil material.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 74
Galium trifidum L.
Fruit of the modern species used for comparison with the fossil material.
(Scale: 1 square in grid = 1 sq. mm. ) 197
Galium trifidum Gray
A number of fruits identifiable with Galium trifidum were ex-
tracted from matrix in several pits. Three fruits from Pit 3 at 111
feet, and four fruits from Pit 4 at 14 feet, were in matrix from in-
side sabre-tooth skulls. About 12 fruits came from Pit A, no depth being given for the matrix (Figure 75).
Most of the fruits are somewhat compressed or nearly flatten- ed; a few are fragmented. Nearly all have the "pad" or area of at- tachment seen in the didymous fruits of modern Galium. The less compressed fruits are 1.0 - 1. 5 mm, and the more or less flattened ones are about 2 mm. in diameter. The surface of the fruits are black, shiny, wrinkled, with no evidence of hairs.
Galium trifidum has an almost cosmopolitan distribution. In
California, it occurs along alluvial marshes and wet meadows at elevations below 5, 000 feet almost throughout the cismontane area.
Occurrence: Rancho La Brea deposits, Pit 3, at 111
foot depth, in matrix from sabre-tooth
skull; Pit 4, at 14-foot depth, in matrix
from sabre-tooth skull; Pit A, no depth
given for matrix.
Collection: Los Angeles County Museum, Plesiotype
Nos. PB. 1456, PB. 1457, PB. 1458. 198
Figure 75 Galium trifidum L.
a. Two of the fossil fruits extracted from matrix in Pit 3 at a depth of 11 i feet. b. Several fossil fruits extracted from the matrix in Pit A; no depth was given.
(Scale: 1 square in grid = 1 sq. mm. ) 199
CAPRIFOLIACEAE Family
Sambucus L.
Sambucus was reported to occur in the Rancho La Brea deposits by Frost (24, p. 83-84) based on two small stems or branches. His identification of Sambucus glauca was made from tangential sections of the second or third growth rings of the fossil and the modern spe- cies. No seeds were mentioned in his report.
A number of Sambucus seeds (nutlets) have been extracted from the matrix in several Pits. No whole berries were found.
In the flora of California there are three to five species of
Sambucus and these are not too clearly defined in the literature (4, p. 44; 58, p. 1047). Much confusion has arisen because one of the species, a shrub or small tree form occurring in valleys, canyons and open flats below 4,500 feet, was called by Jepson (40, p. 965)
Sambucus glauca and was known by that name for many years. S. glauca is now reduced to a synonym with Sambucus coerulea , a spe- cies occurring at elevations up to 10,000 feet. The name now applied to the plant formerly known as S. glauca is S. mexicana.
The fruits and seeds of the following species were studied for comparison with fossil seeds;
Sambucus callicarpa Sambucus mexicana Sambucus coerulea Sambucus mic robot rys Sambucus glauca Sambucus racemosa Sambucus melanocarpa Sambucus velutina 200
In order to be certain that the correct taxon is applied to each specimen, it was necessary to use monographic methods in the classification of the specimens studied. At the same time, the fruits and seeds of all the species were analyzed; these were labeled as above. Sambucus callicarpa is a synonym under S. pubens var. arborescens (4, p. 46). Sambucus glauca in part were assigned to
S. coerulea, and to S. mexicana; S. racemosa in part were assign- ed to S. microbotrys and to S, pubens var, arborescens; and S, velutina was assigned to S. coerulea.
Of these species, Sambucus coerulea and S. mexicana occur within the probable ecological and geographical range of the Rancho
La Brea deposits. Approximately 235 seeds of these two species were studied and compared with the fossil specimens.
Sambucus mexicana Presl, ex DC.
More than a dozen seeds were extracted from matrix removed from the cavities of sabre-tooth skulls in Pit 3 and Pit A (Figure 76) that resemble seeds of Sambucus mexicana in form and surface markings but were slightly smaller perhaps due to shrinkage.
The seeds of all species of modern Sambucus occurring in
California are low convex on the dorsal side and 2-angled on the ventral side, and usually have pitted corrugations on both surfaces.
Seeds of Sambucus mexicana are generally oval to broadly ovate, 201 Figure 76 Sambucus mexicana Presl. a. Fossil seeds extracted from matrix in Pit 3, at depth of 111 feet. b. Fossil seeds extracted from matrix in Pit A; no depth given.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 77 Sambucus mexicana Presl.
Several modern seeds of this species is shown here for comparison with the fossils.
(Scale: 1 square in grid = 1 sq. m 2 02 203
1.5 mm. broad, 2 - 2,3 mm, long, with fairly large irregular pitted
corrugations (Figure 77). The seeds of S. coerulea differed by a
more ovate form, larger size -- usually 2 mm. wide and 2.5 mm.
long, and fine, almost parallel pitted corrugations (Figure 78).
Sambucus mexicana occurs in California, along stream banks,
open flats, and on slopes of low hills, coastal and interior valleys
of the cismontane region from Glenn and Lake Counties south to
Lower California (Map 19).
Occurrence: Rancho La Brea deposits, Pit 3 at
de pth of 11 i feet and at 4 feet;
Pit A -- no depth given.
Collection: Los Angeles County Museum, Plesiotype
No. PB. 1453, PB. 1454, PB. 1455.
COMPOSITAE Family
Many achenes representing a number of genera occur in several pits of the Rancho La Brea deposits. Approximately 179 genera of
Compositae and several thousand species that are present in the
modern flora of California, Much detailed study of achenes would be necessary to identify the specimens in the se deposits . modest attempt was made in order that the many specimens of this family could be represented in this flora. This limited study has
resulted in the following species being identified. 204
Figure 78
Sambucus caerulea Rai.
Several modern seeds of this species shown here for comparison with those in Figure 77, and with those of the fossil in Figure 76. It can be readily seen that Sambucus caerulea are less like the fossils than are those of Sambucus mexicana.
(Scale: 1 square in grid = 1 sq. mm.) 205 i•AP OF CALIFORNIA
This species, mapped here tro p records of field collections, occurs in the California flora in the coastal and
interior valleys of the cisrontane re-
7ion from Glenn and Lake Counties south
to Lower California. Note its near-
ness to the Rancho La Brea deposits. 206
Calycadenia tenella (Nutt. ) Torr. Gray
A single, whole achene and a number of fragments occurred in matrix from Pit 13 and may be assigned to this species with fair degree of certainty. The achene is about 2 mm. long, exclusive of its short, stout, central beak at the areole, and about 1.5 mm, broad at base. It is rugose on the dorsal side and less so on the ventral side. The ventral side is plane while the dorsal side is con- vex with a longitudinal keel down the center Figure 79 shows a specimen whole except for a hole in the dorsal side. The modern achene (Figure 80) appears to resemble it, except that it is slightly smaller.
Calycadenia tenella occurs abundantly in light soil below
2,000 feet. It is endemic and has a limited range, occurring from
Los Angeles County south to Lower California (Map 20).
Occurrence: Rancho La Brea deposits, Pit 13,
Se ct . F -11, at depth of 111 feet.
Collection: Los Angeles County Museum, Paleo-
botany, Plesiotype No. PB. 1440.
Hemizonia fasciculata (DC.) Torr. Gray
A number of achenes that appear to belong to Hemizonia have been extracted from the matrices of several pits. The achenes of the modern species of this genus appear to very closely resemble 207
Figure 79 Calycadenia tenella (Nutt. ) T. and G.
Fossil achenes from Pit 13, Sect. F-11, at depth of 111 feet.
(Scale: 1 square in grid = 1 sq. mm.)
Figure 80
Calycadenia tenella (Nutt. ) T. and G.
Modern achenes of this species shown here for comparison with the fossils.
(Scale: 1 square in grid = 1 sq. mm.) 208
MAP OF CALIFORNIA
Map 20.
gALYCADENIA MAUL& (Nutt.) T. & G.
This species, based on studies of field collections, has a limited range. It is endemic to the coastal area from Los Angeles County south to the Mexican border. Among the collections studied, there were none made near to the fossil area.
■ 209 each other. A comprehensive study of these achenes will be neces- sary before it is certain that one or several species are involved in this collection of achenes.
The fossil achenes (Figure 81) resemble achenes (Figure 82) of Hemizonia fasciculata. They are narrow oblanceolate, 0.75 - 1. 0 mm. wide, 2.0 - 2.5 mm. long, ventral face plane and faintly fine rugose, dorsal side convex with a longitudinal keel and finely to coarsely rugose; a short recurved beak occurs laterally near the apex on the ventral side.
Hemizonia fasciculata occurs along the coastal plains, fre- quently from San Luis Obispo County, south to Riverside County, thence abundantly to Lower California. Map 21 shows this distribu- tion and was mapped from data of field collection in herbaria.
Occurrence; Rancho La Brea deposits, Pit 13,
Sect. F-11, at depth of 114 feet.
Collection; Los Angeles County Museum, Paleo-
botany, Plesiotype No. PB. 1507. 210 Figure 81
Hemizonia fasciculata (DC.) T. and G.
Fossil achenes from matrix inside of skull of sabre-tooth cat, excavat- ed from Pit 13, Sect. F-11, at 11T feet.
(Scale: 1 square in grid = 1 sq. mm. )
Figure 82 Hemizonia fasciculata (DC.) T. and G.
Modern achenes of this species shown here for comparison with the fossils. It will be noted that these specimens are slightly smaller than the fossils but this variation in size occurs normally among the achenes on a single plant,
(Scale: 1 square in grid = 1 sq. mm.) 211 212
MAP OF CALIFORNIA
fCLLJ' CDC.) T. & G.
This species,...-la ! :ped from 1st n on Pield
collections, occurs in the coastal
plains fror,. San Luis Co cflunty
7.outll to RiversiCe COrnty; fro there
south into Lower Colifornic it occurs
more ::,bunntly. :ote its occurrence
in the vicinity of c fossil deposits.
••• sp-0 Rancho La Brea deposits
••• 213
DISCUSSION
It is anticipated that when the identification of the paleobotanical material of the Rancho La Brea deposits is complete, some concept of the climate in this area during the Pleistocene may be formed. At the present time only a portion of this material has been identified and on this basis only limited analysis can be made.
The paleontologists reporting on animal species occurring in the deposits have given varying opinions as to the climatic conditions during the period of accumulations. Compton (16, p. 89), from his studies of the fossil- shrews, considered the climate to be hotter and drier than at present. Dice (20, p. 123), in his report on the fossil rodents, concluded that there was no considerable variation in the climate of the region between the Pleistocene and the present. Miller
(55, p. 252), in his biotic associations of birds, considered the cli- mate of this area to be an arid one; and Miller (57, p. 68) in his study of the fossil birds, suggests the possibility of a warmer climate dur- ing the Pleistocene than is characteristic of Los Angeles at the pres- ent time but he questioned the value of birds as climate indicators.
Because plants are usually excellent indicators of life zones and reflect in their present distribution varying climatic conditions, one may be able to extrapolate a probable climate for the period dur- ing which entrapment occurred. The amount of rainfall in the range 214 of several species contained in this report was studied and are given below: (Most of the data fall within the years 1879 to 1930. )
The average rainfall for the range of Pinus muricata is 25.58 inches, with a high of 37.70 inches and a low of between 16 and 17 inches, This low is in the southernmost extension of its range, and there the trees are not flourishing as well as they are in Mendocino
County where the highest rainfall occurs. From this, one can assume that this species, in order to have lived in the region of deposition, would have required a rainfall of between 20 - 25 inches in order to survive. When the rainfall in this region dropped below 16 inches,
P. muricata became extinct. The range of Sambucus mexicana had an average rainfall of 18.95, a high of 28.23, and a low of 10,82 inches for the period up to 1930; the range of Rhus diversiloba had an average of 34.91 inches, with a high of 73.38 and a low of 15. 99 inches. The range of Acer Negundo var. californica had an average of 23.65, a high of 55.86, and a low of 10.80 inches; the average rainfall for the range of the several species of Arctostaphylos, here- in reported is between 25.90 and 39.78 inches.
Of the total number of species contained in this report, the majority no longer occur locally in the flora of the region or are extinct. Also, the majority of these species attain their best develop- ment in areas where cooler climate prevails than in the Los Angeles area. 215
In the Los Angeles area, the highest rainfall during the period from 1879 to 1930 was 40.29 inches; the lowest, 4.89 inches; and the average for the period of 14.95 inches. The average rainfall of nine stations in southern California for the same period was 24,80 inches.
From these data, it appears that the climate may have been cooler and more moist during the period of deposition, and that spe- cies occurring in southern California would find an average seasonal rainfall of 20 to 25 inches suitable for their continued existence. It may be assumed that when this average dropped below 20 inches for long periods of time, the species either receded to areas with suit- able rainfall or became extinct. 216
SUMMARY
More than 4,000 specimens of fruits and seeds were extracted from the matrix removed from inside the skulls of sabre-tooth cats.
Of this number, approximately 1,445 specimens are involved in this study. These fossil fruits and seeds have been identified with the result that the Rancho La Brea Pleistocene flora comprises 15 fami- lies, 20 genera, and 30 species. Of this number, four species, and four varieties are new to the Pleistocene floras. Eleven of the 30 species occur in the flora of the area today, eleven now occur in areas so remote from the Rancho La Brea site that they could not have been carried by flood waters into the areas of deposition, and therefore must have been living near to the asphalt beds in order that entrapment could occur. Eight of the species are now extinct.
In the naming of new species and varieties, a species of Cornus was named for Dr. Chester Stock, who made it possible for me to study this material. A variety of Cupressus was named for Capt.
John Allen Hancock, who gave the Rancho La Brea deposits to Los
Angeles County, and a new species of Juniperus was named for Dr.
Henry P. Hansen, Palynologist, and Dean of the Graduate School,
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