Corispermum pacificum |
Corispermum |
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common bugseed, Pacific bug-seed |
bug-seed, tick-seed |
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Habit | Plants usually branched from base, (5–)15–40 cm, glabrous or sparsely covered with dendroid hairs (especially when young). | Herbs, annual, with dendroid (branched), sometimes almost stellate hairs, occasionally glabrous, or becoming glabrous at maturity. | ||||||||||||||||||||||||||||||||||||||||
Stems | erect or ascending, rarely prostrate, branched (rarely simple), not jointed, not armed, not fleshy. |
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Leaves | blades narrowly lanceolate, linear-lanceolate, or linear, flat or nearly so, 2–5(–7) × 0.2–0.6 cm. |
alternate, sessile; blade [obovate-elliptic, elliptic], lanceolate, linear-lanceolate, linear, or filiform, flat or convolute at maturity, base truncate, margins entire [indistinctly undulate], apex acute. |
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Bracts | ovate-lanceolate, narrowly ovate-lanceolate, almost ovate, or lanceolate, (1–)1.5–2.5 × 0.3–0.7(–0.9) cm. |
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Inflorescences | usually compact, rather dense, or sometimes ± lax, condensed only near apex, ovoid, oblong-ovate, obovate, broadly linear, or occasionally clavate. |
terminal spikes; flowers solitary in axils of ovate, lanceolate, or linear leaflike bracts (also in axils of middle and lower leaves and branches in C. ochotense and occasionally in some other species). |
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Flowers | bisexual; perianth segments absent or 1(–3), scalelike; stamens 1–3(–5); ovary superior; stigmas and styles 2. |
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Perianth | segment 1, sometimes absent in distal flowers. |
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Fruits | usually black (rarely deep olive green, especially when immature), sharply contrasting with greenish semitransparent wings, without spots and warts, slightly convex abaxially, flat or slightly concave adaxially, orbiculate-obovate to almost orbiculate, broadest near middle (or occasionally slightly beyond), 3–4 × 2.7–3.8 mm, shiny; wing translucent, thin, (0.2–)0.3–0.6 mm wide, margins slightly undulate or indistinctly erose-denticulate, apex rounded or occasionally indistinctly notched. |
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Seeds | vertical; embryo horseshoe-shaped or almost circular; perisperm abundant. |
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Fruiting | structures: style bases at maturity forming characteristic bifid rostrum (“beak”) at apex of achenes [concealed by wing in some species], achenes largely exposed, vertical, sessile, convex to almost plane abaxially, plane, ± concave adaxially, lenticular, ovate, obovate, elliptic, or orbiculate [elongate], margins winged or wingless, apex acute, glabrous and shiny, or maculate and/or slightly verrucose; wing (if present) with entire, undulate, or minutely erose-denticulate margins (in some species emarginate at apex, or long-adnate to style bases); pericarp strongly accrescent to seed or small portions not accrescent, forming small whitish bladders (“warts”). |
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x | = 9. |
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Corispermum pacificum |
Corispermum |
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Phenology | Flowering late summer–fall. | |||||||||||||||||||||||||||||||||||||||||
Habitat | Sandy shores, dunes | |||||||||||||||||||||||||||||||||||||||||
Elevation | 0-500 m (0-1600 ft) | |||||||||||||||||||||||||||||||||||||||||
Distribution |
ID; OR; WA
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North America; Eurasia |
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Discussion | Of conservation concern. Corispermum pacificum seems to be closely related to Siberian C. crassifolium Turczaninov and C. maynense Ignatov. The latter species occurs in the northeastern Russian Far East and may be expected to occur in Alaska. Corispermum pacificum differs from C. maynense by its usually more robust habit, and its wing rounded (rarely rounded-truncate or indistinctly emarginate, but not triangular) at apex. From C. crassifolium it may be distinguished by the constant presence of perianth segments, and more flattened black mature fruits. Corispermum pacificum probably also occurs in adjacent regions of British Columbia. Corispermum pacificum is placed in subsect. Crassifolia (S. L. Mosyakin 1997). This subsection seems to be of Siberian origin, with its central species, C. crassifolium, being closest to the hypothetic ancestral taxon. The presence of perianth segments in C. pacificum may be explained by ancient hybridization with representatives of subsect. Pallasiana. Reproductive isolation between the sympatric species of Corispermum may be achieved by different flowering periods. Occasional hybrids between C. pacificum and C. villosum are similar in their habit to C. pacificum in having usually broad leaves and rather dense inflorescences but they have mostly aborted fruits suggesting that C. pacificum and C. villosum are taxonomically distant species. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Species ca. 65 (11 in the flora). Mature fruits are important and usually necessary for reliable identification of Corispermum. Serial herbarium material showing variability is also desirable. The wing of a fruit should be observed and measured from the abaxial (dorsal) face of a fruit. When observed from the adaxial face, the pale margin marking the position of the hippocrepiform peripheral embryo could be confused for the true wing. For a long time representatives of this genus were believed to be recently introduced to North America from Europe. In the treatment by N. J. Maihle and W. H. Blackwell (1978) only three species were reported for North America: Corispermum hyssopifolium Linnaeus, C. nitidum Kitaibel ex Schultes, and C. orientale Lamarck (all Eurasian). However, it is now clear from both recent taxonomic studies and fossil evidence that Corispermum was present in North America at least 38,000 years b.p. in Alaska and the Yukon, 11,000–14,000 years b.p. in Arizona and Utah, and ca. 4000 years b.p. in New Mexico (for details see C. O. Rosendahl 1948; J. L. Betancourt et al. 1984; J. V. Matthews Jr. 1982; S. B. Young 1982; S. L. Mosyakin 1995, 1997). Native American species of Corispermum are evidently closely related to eastern Asian (especially Siberian) ones, but not to native European taxa. Although specific limits between related taxa in Corispermum are uncertain, a rather narrow species concept is accepted in the present treatment. The author is well aware of possible shortcomings and inconveniences of that approach and agrees with the opinion expressed by W. S. Judd and I. K. Ferguson (1999, p. 406): “It seems clear both that an extremely broad treatment of C. hyssopifolium is not justified, especially since the genus is indigenous in North America, and that a typological approach leading to the recognition of numerous arbitrarily separated microspecies is not useful.” My first intention was to make the treatment consistent with the prevailing Eurasian narrow species concept for the genus applied by M. M. Iljin (1929, 1936), P. Aellen (1961, 1964), M. V. Klokov (1960), M. Kitagawa (1935), Tsien C. P. and Ma C. G. (1979), and others. I also wanted to emphasize the unusual diversity of the native Corispermum taxa in North America. Unfortunately, virtually no experimental taxonomic or field ecological research has been done on taxa of the genus in Asia and North America, and I had no other choice but to rely almost exclusively on herbarium taxonomy and experience with Eurasian taxa. It remains the task of further studies to reveal the precise natural boundaries between North American species of Corispermum and their phylogenetic links to Eurasian taxa. Because of common misidentifications in the past and the limited scope of the current treatment, which was based almost exclusively on herbarium specimens, data on exact distribution patterns of Corispermum species in North America remain deficient and tentative. Corispermum is most abundant in arid regions of Asia, with some species occurring in temperate and subarctic zones. Some species often occur as introduced far beyond their native ranges, and immature specimens are difficult to identify with certainty. Special taxonomic and floristic studies are needed in order to reveal the actual distribution of many Corispermum species in North America. Excluded species: Corispermum orientale Lamarck in J. Lamarck et al., Encycl. 2: 111. 1786 No specimens resembling typical Corispermum orientale were found in North American collections. However, small-fruited and almost wingless specimens of C. villosum may be confused with C. orientale. Corispermum marschallii Steven, Mém. Soc. Imp. Naturalistes Moscou 5: 336. 1817 A specimen of Corispermum marschallii was found by the author at MO among North American specimens (mis)identified as C. hyssopifolium. However, the label is virtually illegible, and probably the specimen was misplaced. No other indication of occurrence of that unmistakable Eurasian species in North America has been found yet. Corispermum sibiricum Iljin, Izv. Glavn. Bot. Sada S.S.S.R. 28: 649. 1929 Records of Corispermum sibiricum from the Great Plains (Great Plains Flora Association 1986) were based on misidentified collections of C. pallasii or C. americanum, which belong to the same subsection. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 4, p. 319. | FNA vol. 4, p. 313. | ||||||||||||||||||||||||||||||||||||||||
Parent taxa | Chenopodiaceae > Corispermum | Chenopodiaceae | ||||||||||||||||||||||||||||||||||||||||
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Name authority | Mosyakin: Novon 5: 345, fig. 1A. (1995) | Linnaeus: Sp. Pl. 1: 4. (1753): Gen. Pl. ed. 5, 5. (1754) | ||||||||||||||||||||||||||||||||||||||||
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