BEN |
BOTANICAL ELECTRONIC NEWS |
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ISSN 1188-603X |
No. 408 April 21, 2009 | aceska@telus.net | Victoria, B.C. |
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The Linnean Society of London announced that the prestigious Jill Smythies Award for Botanical Illustration for 2008 will go to Dr Halina Bednarek-Ochyra, Laboratory of Bryology, Institute of Botany of the Polish Academy of Sciences, Krakow. The Prize is given to a botanical artist for excellence in published illustrations in aid of plant identification, with the emphasis on botanical accuracy and the accurate portrayal of diagnostic characteristics. Halina specializes in bryological artwork, and she completed illustrations for the recently published "The Illustrated Moss Flora of Antarctica". She is also a bryologist, with over 200 scientific works published, who specializes in the Racomitrioideae. In 2006 she published a taxonomic monograph of the genus /Codriophorus/ and, additionally, she is the co-author of two major Floras of Antarctic hepatics (2000) and mosses (2008). Moreover, she serves as the curator of the bryological herbarium at KRAM. The Prize, which comes with a purse and silver medal, will be given to her in a ceremony in London on May 21, 2009.
During the 18th century, Linnaeus inspired 17 of his students to travel to the far corners of the earth to document local nature and culture. Their travel cover all of the known continents and they came to be known as the Linnean Apostles.
The publication of a major international series of eight volumes — in all, 11 books of narratives and approximately 5000 pages has been in preparation for a long time. All of the accounts are published here for the fist time in English; those who left no journals are described through available sources. A team of translators have sweat blood for decades to accomplish this enormous task. I have five of these books so far; they are intriguing and exciting accounts of what field work was like especially in South Africa, Japan, the South Pacific, and eastern North America. It is obvious that Linnaeus’ ties with Dutch botanists, especially their maritime fleets and colonies, made these trips possible. Captain Cook’s early explorations to the Antarctic and South Pacific Islands were important also.
That these students were essentially trained in the botanical aspects of medicine gave these excursions an early example of what we now call "doctors without borders". They treated illnesses and made extensive notes on the medicinals used by the local people, at the same time collecting plants, insects, animals large and small, to fill the museums of Europe. They also made extensive lists of vocabularies, and illustrated landscapes and the large wild game animals of south Africa. Having experienced all this in situ, some really stinging but carefully respectful satire at times is directed at such famous closet-naturalists such as the celebrated M. Buffon. They are not dull. These books speak to us today.
Volume 1 (Introduction) is the descriptive one. Here the reader will get a deeper understanding of the world in which Linnaeus and his apostles lived. The 18th century was both like and unlike our world today. It was during this era that the modern world first saw the light of day. The concluding volume 8 (Encyclopaedia) will include maps, a categorized index for all the volumes, biographical information on each apostle and a complete bibliography of all published material, and a list of the most important collections of scientific material in museums, archives, and libraries connected to the work of the apostles. The intervening books of narratives include those of Thunberg, Sparrmann, Kalm, Rolander, Hasselquist, Solander, and many others. Nothing like this has ever been attempted and is an important addition to the other publications arising from the recent celebration of Linnaeus’ birth. The volumes have given me at least a year’s amount of fascinating reading and education.
Five of the 8-volume series is now available. For detailed information go to http://www.ikfoundation.org/, or http://www.ikfoundation.org/linnaeus/volume-one.html, or write to IK Foundation & Company, P.O. Box 70, Whitby, North Yorkshire YO21 1YD, United Kingdom.
The jewelweeds, Impatiens, are remarkable for their diversity of floral form, showiness, baffling cryptic species, pollination intrigue, and aggressive spontaneous hybrids. As with the hawkweeds, Hieracium, we have a confusing mix of native and introduced species in the Pacific Northwest. Although our jewelweeds are delicate annuals with brittle succulent stems, they are able to sprout and flower in the midst of dense stands of reed canary grass (Phalaris arundinacea L.), a wetland bully notorious for displacing our indigenous flora.
As many children know, the capsules of Impatiens are explosive if squeezed, leading to their popular name touch-me-not. Jewelweeds are members of the Balsaminaceae, a family little known and seldom seen outside of gardens. I’d like to introduce some of the puzzles of our northwestern jewelweeds, as well as provide keys and illustrations for identification. Seek touch-me-nots on the shores of river sloughs, ponds, in riparian forest, and in damp ditches and cranberry farms. Impatiens are sporadic in most areas, except for the extensive populations in the intertidal freshwater marshes of the lower Columbia River (Fig. 1).
The foliage of our three native Impatiens is the same, so to understand the genus you must understand the flowers. They all can produce tiny self-pollinating (cleistogamous) flowers in leaf axils early or late in the season (Fig. 2). This is a relatively quick and inexpensive method of setting seed for an annual. I think of it as a backup strategy, should the elaborate and colorful outcrossing flowers fail to attract a pollinator.
You might assume our recent illustrated floras clarify the floral differences among jewelweeds. But you would be wrong. The Jepson Manual (Hickman 1993) omitted the family due to a printer error (M. Wetherwax pers. comm.). Hitchcock and Cronquist (1961, 1973) are missing recently naturalized garden escapes. Hitchcock and Cronquist (1973) mistakenly illustrates three flowers upside-down. Our most current illustrated regional flora, for British Columbia (Douglas et al. 1998, pp. 6-9), takes inverted flowers as a norm and confuses size and shape of the corollas enough to befuddle identification. I find the upside-down flower art especially amusing, because sometimes visiting bees enter the flowers upside-down, presumably to gather pollen from the anthers at the top of the floral tube (Fig. 3).
The British Columbia flora also fails to mention variable jewelweed, Imaptiens aurella Rydb., can have spotted flowers, does not show I. noli-tangere with a gradual taper to the spur, orients the blossoms of small-flowered touch-me-not, I. parviflora, vertically instead of horizontally, and says the spots of I. capensis are brown, when in life they are red to orange. The BC flora also says the spots of I. noli-tangere are brownish-purple, but the live plants I have seen in America and Asia have dark red spots. Similarly, the Flora of the Pacific Northwest (Hitchcock and Cronquist 1973) illustrates three flowers upside-down, says I. aurella is always unspotted, does not show the abrupt taper to the spur in I. capensis, and inaccurately illustrates the diagnostic small spots, which are primarily dorsal on the tube of I. noli-tangere. I should also note that spotted jewelweed has occasional odd color forms not described in western floras, without spots, or with the corolla white, cream or pale yellow, with spots varying red to bright pink (Fig. 4). Atypical color forms are rare in western Washington, where they are mixed among typical plants.
Why are the illustrations and descriptions such a mess in our floras? Northwesterners are not alone; the confusion goes back to the time of Linnaeus, who mixed up North American collections of I. capensis with I. noli-tangere (Zika et al. 2008). The biology of the genus is at the heart of the problem. As lovers of wet soil, they can support their succulent lifestyle despite our summer drought. But when you pick them, they wither quickly on a hot summer day, soon resembling cooked spinach. As with the violets, their wilted flowers make poor herbarium specimens. So the study of museum vouchers is not as enlightening as it is for other wetland genera like sedges and rushes, which are easy to preserve by drying. A special effort must be made to press Impatiens flowers immediately. I’ve found picking a few extra flowers and pressing them in tissue paper makes a valuable addition to any herbarium collection (Fig. 5).
Fresh Impatiens flowers are striking and different enough to usually allow easy identification. Kashmir balsam, Impatiens balfourii Hook. f., is a pink-flowered rare garden escape east of the Cascade Range and in California (Fig. 6). The gradual taper to the spur is quite different from the abrupt taper to the spur of policeman’s helmet, I. glandulifera Royle, another pink-flowered species naturalized on the coast and in Idaho (Fig. 7). A third Asian introduction grows wild in British Columbia, the aptly named small-flowered touch-me-not, I. parviflora DC., with diminutive pale yellow corollas (Fig. 8).
The jewelweeds with large yellow to orange flowers include all our natives,
and are an interesting group. A key is provided to help in sorting them out.
The most common spurred species west of the Cascades, spotted jewelweed
(Impatiens capensis, Fig. 9), was treated as a northwestern native by many
authors (e.g., Ornduff 1966, Hitchcock and Cronquist 1973, Douglas et al.
1998). Spotted jewelweed is native in eastern North America, and parts of
boreal Canada, but not west of the Rocky Mountains. I came to that
conclusion after looking at hundreds of herbarium collections and wild
populations. All the verified local records for I. capensis begin in 1950,
which is 80-100 years after the start of the collecting record for our three
natives, I. aurella (Fig. 10), I. ecalcarata Blank. (Fig. 11), and I.
noli-tangere (Fig. 12). In addition, I. capensis acts like a recently
introduced weed, and has been spreading rapidly in ditches and disturbed
wetlands over the last half century, while our native species west of the
Cascades are declining as wetland habitat is lost. This by itself may not
sound alarming, but where I. capensis meets I. ecalcarata, the native
and non-native species hybridize. I found these crosses in 87% of the
populations of I. ecalcarata west of the Cascades (Zika 2006a).
A key to flowers of Pacific Northwest Impatiens (based on Zika 2006b)
The showy flowers of spotted jewelweed have large amounts of nectar in their
spurs, so they are well-suited to pollination by ruby-throated hummingbirds
(Temeles and Ewald 1999). Hummingbirds demand a lot of sugar-rich nectar to
power their flight, beating their wings 50 times a second. Ruby-throated
hummers are native to eastern North America, and absent in the Pacific
Northwest, where bees come to the flowers to gather the copious nectar. In
our region spotted and spurless jewelweeds flower at the same time. They
readily hybridize when bees move pollen between the species in mixed stands.
However, spotted jewelweed has that prolific nectar spur, and one study
found it received 77% of the floral visits by honeybees in mixed populations
of jewelweeds. Spurless jewelweed can’t compete; it has no nectar to offer,
and garnered only 4% of the honeybee visits when growing with hybrids and
spotted jewelweeds (Zika 2006a). So times are tough for spurless jewelweed
when spotted jewelweed moves in. My preliminary observations suggest I.
ecalcarata has reduced seed set in the presence of hybrids and spotted
jewelweed.
The hybrid found in these situations is called Pacific jewelweed,
Impatiens ×pacifica Zika, and it grows at more than 50 locations in
western Oregon and Washington. Hybrids combine the characters of its parents
in one of two ways (Table 1). First noted by Robert Ornduff in the 1950s,
Pacific jewelweed is now found from the Seattle area south to Tillamook
County, Oregon (Ornduff 1967; Zika 2006b). The spurless spotted floral form
is unmistakable (Fig. 13). The other form, spurred but unspotted (Fig. 14),
is mimicked by a botanical oxymoron: spotless spotted jewelweed, a scarce
coastal weed. Although there are minor differences in pollen fertility, the
most practical way to separate them is to look for a mix of parents and
hybrids. I found unspotted forms of I. capensis growing in pure stands in
southwestern Washington, and all plants had spurred flowers, while unspotted
I. ×pacifica were always in mixed stands of plants with and without
spurs.
1. Flowers without a spur
2. Flowers without spots ............................................... I. ecalcarata
2' Flowers with spots .................................................. I. x pacifica
1' Flowers spurred
3. Spur ± straight
4. Flowers pink or purple, 10-15 mm from pedicel to spur base (not tip)
......................................... I. balfourii
4' Flowers pale yellow, 1-5 mm from pedicel to spur base .......... I. parviflora
3' Spur strongly curved or hooked
5. Flowers purple, pink or white; spur short; leaves finely toothed
.............................................. I. glandulifera
5' Flowers yellow to orange; spur elongated; leaves entire or coarsely toothed
6. Flowers without spots
7. 9-14 mm from pedicel to spur base (not tip); E side of Cascades
.................................................... I. aurella
7' 14-19 mm from spur base to pedicel; W side
8. All flowers in population spurred
............................ rare spotless forms of I. capensis
8' Some plants with flowers spurred, other plants spurless
................................................. I. × pacifica
6' Flowers with spots
9. 9-14 mm from pedicel to spur base (not tip); E side of Cascades
.................................................... I. aurella
9' 14-19 mm from spur base to pedicel; W side
10. Gradual concave taper to spur; spots primarily dorsal, small and
sparse ............................................ I. noli-tangere
10' Abrupt & convex taper to spur; spots primarily ventral, coarse and
often dense or confluent near throat ................... I. capensis
Species | Spotted corolla | Spurred corolla |
---|---|---|
I. ecalcarata | No | No |
I. × pacifica | No | Yes |
I. × pacifica | Yes | No |
I. capensis | Yes | Yes |
What does one call a spontaneous hybrid between native and introduced species? This is not a simple question. Some botanists say that if non-native plants are involved in a hybrid, then the offspring must be non-native. If you exclude garden hybrids, a counter-argument says all taxa must have evolved somewhere and have a native range. This second view, more or less, was adopted by the author and editors of the Flora of North America treatment of the genus of goatsbeards (Tragopogon), a well-known weedy group of species originating in Eurasia. Some of these introduced species formed spontaneous natural hybrids in southeastern Washington, and subsequently doubled their chromosomes to create new allotetraploids: remarkable goatsbeard, T. mirus Ownbey, and hybrid goatsbeard, T. miscellus Ownbey. They are found occasionally in Pullman and scattered across the western United States, from Arizona to Wyoming. FNA calls them North American native species (Soltis 2006). This is not altogether outrageous; the ancestry of many lines of plants originated through natural hybrids (Dryopteris, Polypodium, Botrychium, many of the asters, fleshy-fruited members of the Rose Family, etc.). Pacific jewelweed, recently formed in Oregon and Washington, has never been found elsewhere, so perhaps the Pacific Northwest could and should be considered its home range.
As Impatiens capensis increases west of the Cascades, I. ecalcarata declines. But any efforts to reduce spotted jewelweed populations must take into account identification difficulties. In particular, surveys and control efforts must be restricted to the west side of the Cascades, and conducted when the plants are in full bloom, so each plant is recognizable. I would recommend some identification training, and only hand culling, with great care and deliberation, to prevent unintended destruction of the native jewelweeds that can grow intermingled with spotted jewelweed. Impatiens are easily pulled out of wet ground, but one can not simply uproot plants “with spots” or plants “with spurs,” because of the possibility of finding new colonies of I. noli-tangere, I. ecalcarata, or I. ×pacifica. No spurless plants should be molested.
If you like the challenge of hunting for rare native species, more field
work might also reveal more populations of Impatiens noli-tangere, which
is occasional in southern British Columbia, but currently known from only
one extant population in the lower 48, in Whatcom Co., Washington.
Similarly, I. aurella occurs in the Blue Mountains and along the Snake
River in southeastern Washington, but has yet to be found in adjacent
northeastern Oregon. It would also be interesting to know how far west the
natural range of I. aurella extends in British Columbia. Does it overlap
at all with the eastward expansion of introduced I. capensis? Does I.
aurella form hybrids with I. ecalcarata, as does I. capensis? Is I.
×pacifica in British Columbia? Does I. noli-tangere form hybrids with
introduced I. glandulifera where their ranges overlap in southwestern BC;
this elusive hybrid has been reported in Europe, but has never been
documented in North America. Field botanists still have much work to do with
the jewelweeds of the Pacific Northwest.
For Figures see: http://bomi.ou.edu/ben/408/impatiens_figures_408.pdf
Fig. 1. Type locality of Impatiens ×pacifica, freshwater intertidal
marsh near Point Adams on the lower Columbia River, Columbia Co., Oregon.
Fig. 2. Self-pollinating (cleistogamous) green flowers, lacking any colored
petals, producing normal fruits and seeds. Impatiens ×pacifica and I.
ecalcarata.
Fig. 3. Bees gathering nectar and pollen from varied jewelweed, native
Impatiens aurella. Legs down or legs up.
Fig. 4. Variation in flower color in non-native Impatiens capensis. Front
view of three dissected flowers, and two flowers in situ.
Fig. 5. Dried Impatiens flowers showing relative size, taper to spur and
spotting. Scale is mm. Flowers picked and pressed separately in tissue
paper. Impatiens aurella, can be dark orange- or red-spotted or spotless;
the taper to the spur can be gradual or abrupt. Impatiens capensis,
typically with abrupt taper to spur and dark orange or red spots, which are
coarse and primarily ventral on the tube. Impatiens noli-tangere, with
gradual taper to spur and typically dark red spots (sometimes drying to dark
purple), which are fine and primarily dorsal on the tube.
Fig. 6. Fresh corollas of non-nativeImpatiens balfourii.
Fig. 7. Fresh corollas of non-native Impatiens glandulifera.
Fig. 8. Fresh corollas of non-native Impatiens parviflora.
Fig. 9. Fresh corollas of non-native Impatiens capensis. Note variation
in density of spots on the front of the flower; spots on floral tube are
coarse and primarily ventral.
Fig. 10. Fresh corollas of native Impatiens aurella. Note presence or
absence of spots.
Fig. 11. Fresh corollas of native Impatiens ecalcarata. No spur, no
spots.
Fig. 12. Fresh corollas of native Impatiens noli-tangere. Note pale
yellow flowers with little spotting on face of flower and fine dark red
spots (primarily dorsal) on the floral tube in side view, and a gradual
taper to the spur.
Fig. 13. Fresh corollas of native Impatiens ×pacifica, spurless spotted
form.
Fig. 14. Fresh corollas of nativeImpatiens ×pacifica, spurred spotless
form, always found in mixed colonies with spurless plants. It looks much
like rare spotless color forms of I. capensis, found in pure colonies of
spurred plants.
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