Johanneshowellia |
Polygonaceae subfam. eriogonoideae |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Howell's-buckwheat |
wild buckwheat |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Habit | Herbs, annual; taproot slender. | Shrubs, subshrubs, or herbs, sometimes nearly arborescent (Eriogonum), perennial, biennial, or annual, homophyllous, polycarpic (rarely monocarpic in Eriogonum); taproot solid or, rarely, chambered (Eriogonum), slender to stout. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Stems | arising directly from the root, weakly erect to spreading, solid, not fistulose or disarticulating into ringlike segments, silky-puberulent. |
prostrate or decumbent to spreading or erect, sometimes scapose, rarely absent (Eriogonum), without recurved spines, glabrous or pubescent, sometimes glandular; nodes not swollen; tendrils absent; caudex stems tightly compact to spreading and at or just below the soil surface or spreading to erect and above the soil surface, woody; aerial flowering stems decumbent to spreading or erect, arising at nodes of caudex branches, at distal nodes of aerial branches, or directly from the root, slender to stout and solid or slightly to distinctly fistulose, rarely disarticulating in ringlike segments (Eriogonum). |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Leaves | usually quickly deciduous, basal, rosulate; petiole present; blade obovate to rounded or somewhat reniform, margins entire. |
deciduous (persistent in some shrubby and matted Eriogonum species), basal or basal and cauline, rarely only cauline, rosulate, alternate, or infrequently opposite (Goodmania) or in whorls of 3 (Gilmania); stipules absent (possibly vestigial in some perennial species of Chorizanthe); petiole present, sometimes indistinct, not articulate or with extrafloral nectaries; blade simple, rarely lobed (Pterostegia), rarely awn-tipped (Goodmania). |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Inflorescences | terminal, cymose; branches dichotomous or trichotomous at proximal node, otherwise dichotomous, not brittle or disarticulating into segments, round, silky-puberulent; bracts 3, connate proximally, triangular or linear to narrowly lanceolate, scalelike or somewhat leaflike, not awned, glabrous to puberulent. |
terminal or terminal and axillary, cymose and dichotomously or trichotomously branched, or racemose, simple or compound umbellate, or capitate; bracts usually connate proximally, leaflike or scalelike, entire apically, sometimes awn-tipped, glabrous or pubescent. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Peduncles | absent. |
absent or erect to deflexed relative to inflorescence branch, sometimes reflexed, straight or curved. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Flowers | 4–7 per involucral cluster; perianth white or pale yellowish to rose or red, broadly campanulate when open, narrowly urceolate when closed, smooth or minutely pustulose abaxially, glabrous; tepals 6, connate 1/4 their length, monomorphic or slightly dimorphic, entire apically; stamens 9; filaments basally adnate, glabrous; anthers white to pale pink, oblong. |
(1–)2–30(–100) per involucral structure, occasionally with stipelike base distal to articulations (Eriogonum); perianth accrescent in fruit, mostly white to red, yellow, light green, greenish white, maroon, or purple, urceolate to campanulate, occasionally glandular or pustulose abaxially, nearly always minutely glandular along midvein adaxially, glabrous or pubescent; tepals (5–)6, in 2 whorls of 3, connate proximally, typically not forming tube (except Chorizanthe, Lastarriaea, Mucronea, Pterostegia), petaloid or, rarely, coriaceous (Lastarriaea), monomorphic or dimorphic, entire, emarginate, or lobed to laciniate apically, rarely awn-tipped (Lastarriaea) or apiculate (Eriogonum); nectary a disk at base of ovary; stamens 3, 6, or 9 (variously 3–9 in Chorizanthe, Mucronea); staminodes absent; filaments usually distinct, occasionally forming staminal tube (Chorizanthe); pistils 3-carpellate, homostylous; ovary 1-locular; ovule 1, orthotropous, placentation basal; styles 3, distinct; stigmas capitate. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Achenes | included, light brown, not winged, 3-gonous, glabrous. |
brown to black or maroon, homocarpic, winged or unwinged, 3-gonous, less often lenticular or globose-lenticular to globose. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Seeds | embryo curved. |
embryo straight or curved. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Involucral | bracts obscure, in tight spiral of (3–)4(–7) distinct, oblanceolate to obovate lobes, bractlike, not awned. |
structures tubular (involucre) or consisting of a series of individual bractlike lobes (involucral bracts) arranged in whorls or spirals, rarely absent (Gilmania), awns present or absent; involucre cylindric, prismatic, turbinate, campanulate, urceolate, or funnelform with 3–8(–36) usually erect teeth or 4–12 spreading to reflexed lobes (teeth and lobes are distal portions of proximally connate involucral bracts); involucral bracts in 1–3 whorls, rarely in spirals (Johanneshowellia), free or connate only at base, linear to oblanceolate or ovate. |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Johanneshowellia |
Polygonaceae subfam. eriogonoideae |
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Distribution |
w United States |
Mainly temperate regions of w North America (Alaska to Mexico); uncommon in South America (Argentina and Chile) and e North America (WVa s to c Fla, e to Mo, Okla, and Tex) |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Discussion | Species 2 (2 in the flora). With recognition of Johanneshowellia, all members of Eriogonum have their involucral bracts fused into a distinct, turbinate to campanulate or hemispheric, tubular structure. In Johanneshowellia, the four to seven, distinct, involucral bracts are arranged in a tight spiral. Each 0.5–1.2 mm, awnless, entire to deeply lobed bract subtends a flower-bearing pedicel. These involucral bracts are themselves usually obscured by inflorescence bracts that subtend each node. As a result, care must be taken to observe the true nature of the involucral complex. The genus is allied with Eriogonum subg. Oregonium. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Genera 20, species ca. 325 (19 genera, 281 species in the flora). Detailed habitat, elevation, and distribution data for the eriogonoid genera are maintained by the author and available on the Web at: “Eriogonoideae (Polygonaceae) of North America north of Mexico” (http://www.life.umd.edu/emeritus/reveal/pbio/eriog/key.html). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Key |
|
|
||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Source | FNA vol. 5, p. 443. | FNA vol. 5, p. 218. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Parent taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Subordinate taxa | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Synonyms | Eriogonum unranked Puberula | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Name authority | Reveal: Brittonia 56: 299. (2004) | Arnott: in M. Napier, Encycl. Brit. ed. 7, 5: 126. (1832) | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Web links |