Plantae

Plants

Friday Flower – Sedum pulchellum

/ Ted C. MacRae / 9 Comments

I’m particularly enamored with glades, and after nearly 30 years of exploring Missouri’s Ozark Highlands, there aren’t many glades of any significance that I haven’t visited at some time or another.  However, during my mostly unproductive Memorial Day weekend collecting trip, I had a chance to visit Bona Glade Natural Area in Dade County for the first time.  Located in southwestern Missouri where the Ozark woodlands of the Springfield Plateau begin transitioning to the grasslands of the Great Plains, this small (20 acres) sandstone glade is noted as a station for the federally threatened and state endangered Geocarpon minimum.  I did not see this diminutive plant (sometimes called tinytim) during my visit, but I did see another pretty little succulent – Sedum pulchellum.  Also called widowscross, this plant belongs to the Crassulaceae – the same family as the familiar jade houseplant.

Although not nearly as rare as Geocarpon, widowscross is nevertheless somewhat restricted in Missouri, occurring primarily in the southwestern quarter of the state.  Throughout much of its range it is primarily associated with calcareous limestone glades, ledges, and outcrops (Baskin and Baskin 1977), but in Missouri it grows also on acidic chert and sandstone glades (Yatskievych 2006) – as is the case at Bone Glade.  I’ve not encountered this plant before, thus when I spotted this little stand with its profusion of brilliant pink blossoms, it immediately caught my attention.  A winter annual, this species prefers full sun and well drained, disturbed soils and apparently produces seeds quite prolifically when grown under the right conditions.  These features, along with its petite attractiveness, would seem to make it an ideal native alternative for succulent gardens.

Another, much less common sedum also occurs at Bona Glade, Sedum nuttallianum (Nuttall’s sedum).  This species is similar to S. pulchellum but can be distinguished by its smaller leaves and yellow blossoms.  It’s range is similar to that of Geocarpon, growing almost exclusively on chert and sandstone glades from southwestern Missouri and southeastern Kansas south to Louisiana and Texas.  I did not see this plant either – in fact, after finding this small stand of S. pulchellum I searched the entire glade rather thoroughly and did not see any other plants of that species either.

Photo Details: Canon 50D (ISO 100-200, 1/400-500 sec, f/5.6), Canon 100mm macro lens, ambient light. Post-processing: minor cropping, levels, unsharp mask.

REFERENCES:

Baskin, J. M. and C. M. Baskin. 1977. Germination ecology of Sedum pulchellum Michx. (Crassulaceae). American Journal of Botany 64(10):1242-1247.

Yatskievych, G. 2006. Steyermark’s Flora of Missouri, Volume 2. The Missouri Botanical Garden Press, St. Louis, 1181 pp.

Copyright © Ted C. MacRae 2010

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Friday Flower – Dwarf Spiderwort

/ Ted C. MacRae / 21 Comments

Living at the foothills of the Ozark Highlands, I sometimes forget how unique the biota of this ancient landscape truly is. More than 200 species of plants and animals are largely restricted to the region, with around 160 of these being true Ozark endemics found nowhere else on earth. The biodiversity of the region stems from the landform’s unusual geology, topography and hydrology, it’s ectotonal position within the North American continent, and its distinction as the only significantly elevated landform between the Appalachian and Rocky Mountains. Many Ozark endemics are found in the region’s abundant caves and sinkholes, formed by underground dissolution of its massive limestone/dolomite bedrocks. Others represent isolated populations of more typically northern plants and animals that found refuge here during the Pleistocene glacial advances. Still others evolved during periods of isolation when vast inland seas covered much of the continent’s interior.

Tradescantia longipes, known locally as dwarf spiderwort or wild crocus, is a particularly exquisite Ozark endemic found scattered in dry igneous woodlands of the Missouri’s St. Francois Mountains and Arkansas’ Ouachita Mountains. I first saw this species two years ago in May at Crane Lake in the heart of the St. Francois Mountains, and the plants shown here were seen this past April in the igneous woodlands of Sam Baker State Park at the southernmost extent of the St. Francois Mountains’ igneous exposures. The genus to which this plant belongs contains some much more widely distributed (though no less striking) members (e.g. T. ohioensis, which I featured in my first “Friday Flower” post). Tradescantia longipes flowers are similar to those of T. ohioensis, but the plant differs from most others in the genus by its short, squat habit of growth and strictly basal leaves.

One feature shared by T. longipes with all other members of the genus is the dense fringe of hairs arising from the stamen filaments.  I discussed these in my first Friday Flower post, noting that each of the 70-100 hairs per filament is composed of a chain of about 20 large, single cells – easily seen with low magnification. While their sensitivity to radiation and chemical mutagens has been recognized for many years (the hairs turn pink when exposed to radiation), less seems to be known about their natural function for the plant.  It is interesting to note, however, that the flowers of Tradescantia and related genera rely heavily on insects for pollination (primarily bees and bee flies), yet they do not produce nectar.  Faden (1992) has speculated that the stamen hairs might combine with floral scents and the nearly pollenless anthers to deceptively attract insects, provide footholds, retain pollen fall, and influence the pollen-collecting behavior of the insects.

Photo Details: Canon 50D (ISO 100, 1/250 sec, f/14-18), Canon 100mm macro lens, Canon MT-24EX flash (1/4 ratio) w/ Sto-Fen diffusers. Post-processing: levels, unsharp mask, minimal cropping.

REFERENCE:

Faden, R. B.  1992. Floral attraction and floral hairs in the Commelinaceae.  Annals of the Missouri Botanical Garden 79(1):46–52.

Copyright © Ted C. MacRae

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Friday Flower – Pawpaw

/ Ted C. MacRae / 28 Comments

As my friend Rich and I stood in the verdent understory admiring the spectacular panicles of red buckeye punctuating the green lushness, a small brown flower on a leafless branch above me caught my eye.  “Pawpaw!” I exclaimed, perhaps partly in amazement that it took us awhile to notice the trees that were, in fact, all around us.  Pawpaw (Asimina triloba) is a member of the only temperate genus in the otherwise exclusively tropical and subtropical family Annonaceae (Custard Apple Family).  Although not nearly as restricted in occurrence in Missouri as the red buckeyes with which they were growing, they are nevertheless always a treat to see. Scattered throughout the state, they can be found growing in bottomland forests, ravines in mesic upland forests, along woodland streams, and at bases of bluffs (Yatskievych 2006).

Pawpaws are, of course, famous for their large edible fruits, sometimes called Indian bananas, Missouri bananas, Michigan bananas, [insert eastern state here] bananas, etc.  Technically, however, the pawpaw fruit is a berry, since it is derived from a single pistil and has multiple seeds embedded within the pulpy matrix.  I’ve not tried the fruit myself, not for lack of desire but rather an inability to find them when they ripen in fall before the birds and mammals get to them.  Some effort has been made to cultivate the plant for fruit production, but low fruit set seems to be a persistent problem due to reproductive self-incompatibility.

Pawpaw also famously serves as the larval food plant for the zebra swallowtail butterfly, Eurytides marcellus (family Papilionidae).  Beyond this, however, there seem to be not many insects associated with the plant.  I have collected dead wood of pawpaw in an effort to determine the species of wood-boring beetle species that are associated with it.  The only species I’ve reared is the longhorned beetle, Elaphidion mucronatum (whose common name “spined oak borer” belies the fact that it is one of the most polyphagous of all North American species), and two other longhorned beetles, Eupogonius pauper and Urgleptes querci (also highly polyphagous), have also been reported being reared from dead wood of this plant.  I have not associated any jewel beetles with pawpaw, nor have any such associations been reported in the literature.  It would appear that woodboring beetles are not fond of the soft, weak wood of pawpaw, perhaps due to the plant’s annonaceous acetogenins with known pesticidal qualities (Ratnayake et al. 1993) (acetogenins are also under investigation as anti-cancer drugs).  Other poisonous compounds, chiefly alkaloids, are found in various parts of the plant, especially the seeds and bark, and likely play a role in herbivore defense. Insect pollinators also seem to be infrequent, as I have not noted any insects on its flowers. Most members of the family are pollinated by beetles (Yatskievych 2006), but the meat-colored, downward-facing, not-so-sweet-smelling flowers of pawpaw suggest pollination by flies, perhaps those attracted to carrion.

REFERENCE:

Ratnayake, S., J.K. Rupprecht, W.M. Potter, and J.L. McLaughlin. 1993. Evaluation of the pawpaw tree, Asimina triloba (Annonaceae), as a commercial source of the pesticidal annonaceous acetogenins. p. 644-648. In: J. Janick and J.E. Simon (eds.), New Crops. Wiley, New York.

Yatskievych, G. 2006. Steyermark’s Flora of Missouri, Volume 2. The Missouri Botanical Garden Press, St. Louis, 1181 pp.

Copyright © Ted C. MacRae 2010

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Friday Flower: Red Buckeye

/ Ted C. MacRae / 14 Comments

Beetles, spiders, and snakes were not the only delights that Rich and I saw as we hiked the lower stretch of the Ozark Trail’s Wappapello Section in early April.  Entering the rich, moist, east-facing slopes overlooking the Black River valley, the oaks and hickories were still in the early stages of bud break. A lush, green understory, however, spread out before us, punctuated by the striking inflorescences of red buckeye, Aesculus pavia (family Hippocastanaceae). Among the first trees to bloom in spring, red buckeye is unmistakable in the field due to its red flowers and palmately divided leaves.

Red buckeye is native to the southeastern U.S., just reaching Missouri in the southeastern Ozarks (though cultivated further north). This makes it less well-known than the more widely distributed Ohio buckeye, Aesculus glabra (absent only from the southeastern lowlands and northwestern corner of the state, and easily distinguished by its white inflorescences, larger size, and spreading growth habit).  Like that species, the seeds and young foliage especially are poisonous if eaten due to glycosidic alkaloids and saponins.  Native Americans roasted, peeled and mashed the nuts into a meal called “Hetuck.”

I first encountered this species in 2001 along Fox Creek in the White River Hills of extreme southwestern Missouri.  It was one of several species that I had selectively “cut” and left in situ for a season to allow infestation by wood boring beetles.  I retrieved the wood the following spring and reared five species of longhorned beetles (family Cerambycidae) from the dead branches, including Astyleiopus variegatus, Hyperplatys maculata, Leptostylus transversus, Lepturges angulatus, and the prize – the very uncommonly encountered Lepturges regularis. All of these represented new larval host records; however, it was not until after I published those records (MacRae and Rice 2007) that I realized the plant itself was not known by Steyermark (1963) to occur naturally outside of the southeastern Ozark Highlands.

Speaking of early spring flowers, many such delights can be found at Berry Go Round #27 which is now up at Mary Farmer’s A Neotropical Savanna. It’s not just spring ephemerals, however, as another Missouri blogger and I show that winter has it’s own botanical charms. Stop by and enjoy the feast!

REFERENCES:

MacRae, T. C. and M. E. Rice. 2007. Distributional and biological observations on North American Cerambycidae (Coleoptera). The Coleopterists Bulletin 61(2):227–263.

Steyermark, J. A. 1963. Flora of Missouri.  The Iowa State University Press, Ames, 1728 pp.

Copyright © Ted C. MacRae 2010

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North America’s second-rarest pine

/ Ted C. MacRae / 13 Comments

Jeffrey (L) and Washoe (R) pines at Galena Creek Park

During last year’s trip to Lake Tahoe, I made it a goal to find all of the 11 conifer species occurring naturally in the Lake Tahoe Basin.  It took some effort, some good references (Arno 1973, Graf 1999, Lanner 1999, and Peterson 1975), and the help of an especially knowledgeable associate at the U.S.D.A. Forest Service headquarters in South Lake Tahoe, but I succeeded in my quest and later wrote two posts covering the Lake Tahoe conifers (Trees of Lake Tahoe – The Pines, Trees of Lake Tahoe – The “Other” Conifers).  In the first of the posts covering the six species of pines, I added the following footnote:

Two additional species of pine – Washoe pine (Pinus washoensis) and single-leaf pinyon pine (P. monophylla) – are often treated as occurring in the Lake Tahoe area. However, they are of sporadic occurrence on the eastern slopes of Mount Rose, and thus do not occur within the Tahoe Basin proper.

Of these, I am quite familiar with single-leaf pinyon pine.  Widespread on isolated mountain ranges throughout the Great Basin into eastern and southern California and Baja California Norte, I have encountered it during many of my field trips out west and reared a number of buprestid species from its tough, scrubby branches (including 2 specimens of the rarely encountered Phaenops piniedulis).  The other species, Washoe pine, was a new one on me, and it is, in fact, the second-rarest species of pine in all of North America (Torrey pine, Pinus torreyana, being the rarest).  Well, that was all it took to make me commit to finding this species on this year’s return to Lake Tahoe.

Washoe pine cones surround a larger Jeffrey pine cone.

Washoe pine grows only in a few locations, primarily in northern California with the best stands found in the Warner Mountains in Modoc County.  In the Tahoe area, Washoe pine grows only on the eastern slope of Mt. Rose in Nevada, where it is limited to the upper reaches of Galena Creek (Graf 1999, Lanner 1999).  It is apparently very similar to Jeffrey pine (P. jeffreyi) – the most common pine in the Tahoe area – but seems to be more closely related to ponderosa pine (P. ponderosa), which occurs at lower elevations and barely makes it up to the Tahoe area (some authorities even question the distinctiveness of this species, instead considering it a high elevation variety of ponderosa pine).  All three species are 3-needled and grow into tall, pyramidal trees with widely spaced horizontal branches.  Like ponderosa pine, the bark of mature trees forms broad yellowish plates separated by black fissures (the bark of Jeffrey pine is often more reddish with plate more narrowly separated).  The resin of Washoe pine is also chemically similar to that of ponderosa pine, both of which differ from the heptane-producing resin of Jeffrey pine.  However, Washoe pine cones more closely resemble those of Jeffrey pine, being somewhat smaller but sharing the “inward-curved” prickles on the scale tips that make them easy to handle (those of ponderosa pine point outwards, making them very prickly to handle).

Ponderosa (L) and Washoe (R) pine cones. Note smaller size and outward-pointing spines of ponderosa pine cone.

Jeffrey (L) and Washoe (R) pine cones. Both have inward-pointing spines, but Washoe pine cone is smaller and more loosely built.

None of my references had any specific locality information for Washoe pine beyond what I’ve stated above, but a little bit of Google snooping through conservation action plan documents revealed that the species occurred at Galena Creek Park, so early in the morning daughter Madison and I made the one-hour drive from South Lake Tahoe to the park.  Arriving at the park, I was disappointed to find nobody manning the headquarters, no maps in the park information board – indeed, no information whatsoever about the occurrence of Washoe pine within the park and where it might be found.  The only clue that there was something special about the pines at this place were the wooden signs around the parking and picnic areas stating “Collection of pine cones prohibited.” I reasoned that it would be very difficult to distinguish the species by its needles, bark, or form, but that the pine cones should be easier to distinguish. I also had no idea whether the pines would occur close to the parking area or if we would need to hike into the area to find them.  So, we just began picking up pine cones.  For a time, all of the pine cones seemed to be typical Jeffrey pine (abundant in the area) with an occasional ponderosa pine (just making up the 6,200′ of elevation in this area).  Ever concerned that I might be missing a subtle difference, I studied each “Jeffrey” pine cone carefully looking for any reason to regard it as truely smaller than normal.  Within about 15 minutes, however, we found it!  Picking up the pine cone, it had the compact build and inward-pointing spines of a Jeffrey pine, but it was smaller and a little more loosely built.  I looked at the trees above and could see no difference from what I would expect for a Jeffrey pine.  Further looking revealed numerous cones of the same type – each tree we found them under was otherwise indistinguishable from Jeffrey pine (at least to this eastern U.S.-based wannabe botanist).  Nevertheless, it was clear that we had found Washoe pine, and that it was quite abundant within this small watershed that we were exploring.  Jeffrey pine was also common in the watershed, and an occasional ponderosa pine could be found.  I took photos of mature individuals of each of the three species, identified conclusively by way of the cones found underneath them, to show how similar in appearance the three species are.

Pinus ponderosa

Pinus jeffreyi

Pinus washoensis

Madison and I later hiked out of the watershed into the higher elevations of Mt. Rose (from where these ants were photographed) – we noticed that almost immediately upon hiking out of the watershed the Washoe and ponderosa pines disappeared, and only Jeffrey pines were seen.  Although I have seen it many times before, I was still hoping to see single-leaf pinyon pine, but none were seen.

REFERENCES:

Arno, S. F. 1973. Discovering Sierra Trees. Yosemite Association, Yosemite National Park, California, 89 pp.

Graf, M.  1999. Plants of the Tahoe Basin.  Flowering Plants, Trees, and Ferns.  A Photographic Guide. California Native Plant Society Press, Berkeley, 308 pp.

Lanner, R. M.  1999. Conifers of California.  Cachuma Press, Los Olivos, California, 274 pp.

Peterson, P. V., and P. V. Peterson, Jr.  1975. Native Trees of the Sierra Nevada.  University of California Press, Berkeley, 147 pp.

Copyright © Ted C. MacRae 2010

Winter Botany Quiz #6 – answers and a checklist

/ Ted C. MacRae / 7 Comments

I thought yesterday’s Winter Botany Quiz #6 would be a fairly difficult, and given the apparent difficulty of my previous quizes (Pismire Puzzle and Tuesday Teaser) I thought I’d give readers a break this week and narrow down the location to the Lake Tahoe area. Despite publishing in the dead of night, it took only 31 minutes for Peter Yeeles to swoop down and correctly name the family, genus, species, and function for the structure pictured. His only lapsus regarded the terminology used for the name of the structure itself, leaving the door open for James Trager to snag some scrap points. The plant is, of course, Cercocarpus ledifolius (curl-leaf mountain mahogany) in the family Rosaceae, and the structures pictured above and in the previous post are the stigmas of the flowers persisting as wind-assisted dispersal structures for the fruit. “Cercocarpus” is, in fact, derived from the Greek words for “tailed” and “fruit”, whose numerous erect hairs give the plant in a silvery sheen late in the growing season.

Why was I interested in this plant? It was one of the few tree species occurring in the Lake Tahoe Basin that I wasn’t able to find for last year’s 3-part series, Trees of Lake Tahoe (including The Pines, The “Other” Conifers, and The Deciduous Trees).  Widespread in the mountainous west (and barely qualifying as a tree), its occurrence in the Tahoe Basin is more sporadic.  Better stands are found outside the basin proper on the dry eastern flank of the Sierra Nevada (Graf 1999), and indeed these plants were photographed at ~6,500 feet on the eastern slopes of Mt. Rose.

My real interest in Cercocarpus, however, is as a favored host plant for species of jewel beetles (family Buprestidae).  About two dozen species of these beetles have been associated with Cercocarpus spp. in North America, nine of which have been confirmed as breeding within dead branches of these plants and five having been associated with no other plant.  I’ve collected a number of these species myself, particularly in the San Gabriel and Santa Rosa Mountains of southern California and the Chisos Moutains of Big Bend National Park in Texas, including Polycesta cazieri, Chrysobothris piuta, and paratype specimens of Acmaeodera rubrocuprea. I thought it might be of interest to any readers who might collect these insects to present a checklist of Buprestidae associated with Cercocarpus in North America (see appendix below).

REFERENCE:

Graf, M. 1999. Plants of the Tahoe Basin. Flowering Plants, Trees, and Ferns. A Photographic Guide. California Native Plant Society Press, Berkeley, 308 pp.

Checklist of North American Buprestidae associated with Cercocarpus

(Bold indicates species that have been reared from Cercocarpus.  An asterisk indicates species that have been associated exclusively with Cercocarpus).
– Acmaeodera (s. str.) angelica Fall
– Acmaeodera (s. str.) connexa LeConte
– Acmaeodera (s. str.) dolorosa dolorosa Fall
– Acmaeodera (s. str.) idahoensis Barr
– Acmaeodera (s. str.) mariposa mariposa Horn
– Acmaeodera (s. str.) mariposa dohrni Horn
– Acmaeodera (s. str.) nelsoni Barr
– Acmaeodera (s. str.) nexa Fall
– Acmaeodera (s. str.) plagiaticauda Horn
– Acmaeodera (s. str.) pubiventris lanata Horn
– Acmaeodera (s. str.) rubrocuprea Westcott & Nelson*
– Acmaeodera (s. str.) vandykei Fall
– Acmaeodera (s. str.) variegata LeConte
– Acmaeodera (Squamodera) vanduzeei (Van Dyke)
– Anthaxia (Haplanthaxia) caseyi sublaevis Van Dyke
– Anthaxia (Melanthaxia) porella Barr*
– Anthaxia (Melanthaxia) simiola Casey*
– Chrysobothris bisinuata Chamberlin*
– Chrysobothris mali Horn
– Chrysobothris piuta Wickham
– Chrysobothris purpureovittata purpureovittata Horn
– Chrysobothris purpureovittata cercocarpi Westcott & Nelson*
– Dicerca (s. str.) hornii hornii Crotch
– Polycesta (Tularensia) californica LeConte
– Polycesta (Tularensia) cazieri Barr

Copyright © Ted C. MacRae 2010

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Winter Botany Quiz #6

/ Ted C. MacRae / 7 Comments

This photo was taken during my March trip to Lake Tahoe.  Can you identify the plant (family, genus, species), the structure shown, and its function?  Answer and more photos tomorrow.

© Ted C. MacRae 2010

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Bicycle ride around Lake Tahoe

/ Ted C. MacRae / 6 Comments

Overlooking Emerald Bay from Emerald Bay Pass.

Perhaps some of you have by now deduced that, in addition to insects and natural history, I have a second passion – cycling! In fact, I raced bikes competitively as an amateur for seven years (going by the local nickname “BugMan“) before hanging it up at the end of 2008.  However, even though I’m not racing anymore, I still ride as much as ever, only now it’s purely for the fun of it!  I’m a dedicated roadie, riding year-round and averaging around 5,000-6,000 miles a year.  I love the speed and the smoothness of the road and the opportunity it provides to cover long distances and enjoy the sights (not to mention the resulting freedom to eat like a horse and stay relatively trim!).

One of my most memorable cycling experiences was in 1995, when I joined a group that rode the entire circuit around Lake Tahoe.  I was living in Sacramento at the time and was a relative newbie – the 72-mile ride with 3,500 feet of climbing at elevations ranging from 6,200 feet at lake level to more than 7,000 feet near Carson Pass was without question the most difficult ride I had ever attempted at that point.  Now, as a seasoned ex-racer, such a ride is not extraordinarily difficult for me – in fact, I do rides in the 60-80 mile range with as much climbing or more almost every weekend.  Still, my memories of the challenge and the unbelievable scenery have kept that ride high in the ranks of my most epic, and since we began going back to Lake Tahoe two spring ago I’ve wanted to do it again.  It would not have been possible during our first trip back, as the roads still had quite a bit of snow on them; however, last year the roads were clean and dry, and I resolved to bring my bike with me on this year’s trip in the event that such was again the case.  Madonna del Ghisallo (patron saint of cycling) must have been smiling down upon me, because this year the roads were again in beautiful condition, despite the amount of snow blanketing the surrounding landscapes.  It made for one of the most beautiful bike rides I have ever done in my life.

There was a comforting familiarity to the ride, despite the 15 years since the last – the stunning landscape that I have come to cherish so dearly, the massively shaded solitude of the west shore, lunching on California cuisine in a quaint village along the north shore, and the long climbs and screaming descents through open Jeffrey pine forests along the east shore.  It was also different – I was by myself, yet despite that I was stronger and briming with confidence; not only a seasoned cyclist, but also much more knowledgeable of and closely attuned to the natural history of the area.  I didn’t fear the climbing, I relished it!  I didn’t overcome the challenge, I enjoyed it!  I stopped at a few places to take photographs (taken with my small point-and-shoot, for obvious reasons) and share some of them here – I hope they give you a tiny taste of the flavor of that day.

Near the summit of Emerald Bay Pass, looking back at Mt. Tallac.

High point on Emerald Bay Pass.

The descent to Eagle Falls at Emerald Bay.

 This is an avalanche zone (note deep snow deposits on steep slopes on left side – these extend high up the mountain here).  Moments after taking this photo, an avalanche fell onto the road right as I was descending by this spot. At ~35 mph there was no stopping – I rode right through it as the initial snow drop hit the pavement and then watched in amazement as the main drop dumped onto the road behind me.  It was not big enough to bury anything, but I surely would have crashed had I gotten there just a moment or two later!

Overlooking Emerald Bay from Emerald Bay Pass.

Emerald Bay is a glacial scour formed during the last glacial period ending only 10,000 years ago. Fannette Island, Lake Tahoe’s only island, is thought to be a resistant rib of granite rock that was overridden by the glacial ice. Lateral glacial morraines enclose each side of the bay, and an incomplete terminal morraine connects Emerald Bay to the main lake. Last year, I stood atop the outermost rock of the left side of the terminal morraine and took photographs looking back in this direction. 

Grove of sugar pines at D. L. Bliss State Park.

Sugar pine, Pinus lambertiana, is among my favorite of all pines.  More common on the west shore due to their preference for higher levels of moisture, their towering, ragged, asymmetrical crowns with long, pendulous cones (usually a foot or more in length) hanging from the branch tips are immediately recognizable from afar.  These majestic trees are the world’s tallest pine and bear the longest cones in the genus; they stand in defiant contrast to the uniformly symmetrical crowns of the more common Jeffrey pines (Pinus jeffreyi) and white firs (Abies concolor) that surrounded them.  For a more thorough treatment of the trees of Lake Tahoe, please visit my three-part series covering the pines, the “other” conifers, and the deciduous trees.

Some might think it was still a little too early in the season for bike riding.

Looking west across Lake Tahoe from Logan Shoals Overlook.

The east shore in Nevada is decidedly drier than California’s west shore.  The forest on the Nevada side is a more open, fire-mediated landscape dominated by Jeffrey pine, as opposed to the denser forests on the west shore with higher incidence of shade-tolerant trees such as white fir and incense-cedar (Libocedrus decurrens).

View of Cave Rock (left center) from Logan Shoals Overlook.

Cave Rock was and still is a sacred place for people of the Washoe tribe, whose ancestors occupied Lake Tahoe during the summers and performed religious ceremonies inside the largest of its caves.  These caves, sitting several hundred feet above the current lake level, were carved by wave action shortly after Lake Tahoe’s formation nearly 3 million years ago when lake levels were much higher than they are today.  The first of two highway tunnels was blasted through the rock in 1931 (much to the dismay of the Washoes), and the second was added in 1957.

Looking north along Lake Tahoe's east shore from atop Logan Shoals Overlook.

Copyright © Ted C. MacRae 2010

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