Gayophytum diffusum |
Gayophytum racemosum |
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diffuse groundsmoke, spreading groundsmoke |
black foot gayophytum, black-foot groundsmoke, racemed groundsmoke, racemose groundsmoke |
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Habit | Herbs usually glabrous to strigillose, sometimes villous. | Herbs glabrous or strigillose, rarely villous. | ||||
Stems | erect, branched or unbranched near base, much branched distally, usually with 1 or 2 nodes between branches, distal branching dichotomous or lateral branches shortened, 5–60 cm. |
erect or spreading, branched mostly proximally, secondary branches few or none, branching not dichotomous, (5–)10–40 cm. |
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Leaves | reduced distally, 10–60 × 1–5 mm; petiole 0–10 mm; blade very narrowly lanceolate. |
little reduced distally, crowded, 10–25 × 1–3 mm; petiole 0–5 mm; blade narrowly lanceolate or elliptic to sublinear. |
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Inflorescences | with flowers arising usually as proximally as first 1–20 nodes from base. |
with flowers arising as proximally as first 1–3 nodes from base. |
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Flowers | sepals 0.9–3(–5) mm, reflexed singly or in pairs; petals 1.2–5(–7) mm; pollen 90–100% fertile; stigma hemispheric to subglobose, exserted beyond anthers of longer stamens or surrounded by them at anthesis. |
sepals 0.8–1.4 mm, reflexed singly or in pairs; petals 1.3–1.8 mm; pollen 90–100% fertile; stigma subglobose, surrounded by anthers at anthesis. |
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Capsules | ascending to reflexed, subterete, 3–15 × 1–1.5 mm, with inconspicuous or conspicuous constrictions between seeds, valve margins somewhat undulate, all valves free from septum after dehiscence, septum straight or sinuous; pedicel 2–10(–15) mm, usually shorter than capsule. |
ascending, flattened, 10–15 × 0.8–1.4 mm, not constricted between seeds, valve margins entire or slightly undulate, all valves free from septum after dehiscence, septum straight; pedicel 0.4–2 mm. |
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Seeds | (3–)6–18, all or most developing, arranged ± parallel to septum and in alternating pattern between locules, crowded, overlapping, often appearing to form 2 irregular rows in each locule, or well spaced, forming a single row in capsule, brown, sometimes mottled with gray, 1–1.6 × 0.5–0.8 mm, glabrous or puberulent. |
(10–)14–34, all developing, arranged obliquely to septum and subopposite seeds in adjacent locule, forming 2 even rows in capsule, light to dark brown, 0.8–1 × 0.3–0.5 mm, glabrous or densely puberulent. |
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2n | = 28. |
= 28. |
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Gayophytum diffusum |
Gayophytum racemosum |
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Phenology | Flowering May–Oct. | |||||
Habitat | Drying margins of meadows and pools. | |||||
Elevation | 1000–4000 m. (3300–13100 ft.) | |||||
Distribution |
w North America; n Mexico
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AZ; CA; CO; ID; MT; NV; OR; SD; UT; WA; WY; AB
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Discussion | Subspecies 2 (2 in the flora). Gayophytumdiffusum consists of a diverse assemblage of tetraploid populations, some of which are similar to every known diploid species except G. humile. The combination of characteristics of at least five diploid species in various ways suggests that the complex is derived from several independently formed allopolyploids that subsequently hybridized and segregated to produce the observed diversity. Populations of Gayophytum diffusum differ in breeding behavior. Populations with relatively large flowers and stigmas that extend beyond the anthers are obviously outcrossing, whereas most populations are small-flowered and modally self-pollinated. It is among the latter that the greatest morphological diversity is found. Often two or more morphologically different, apparently true-breeding strains can be found growing together. In such a variable complex, recognition of infraspecific taxa becomes arbitrary. In this treatment the striking morphological differences associated with breeding behavior have been used as a basis for subspecies recognition. At some localities the two subspecies intergrade. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Gayophytum racemosum, on the basis of morphological and ecological observation, appears to be an allotetraploid derived from hybridization between G. decipiens and G. humile or a related species that is presumably extinct. Gayophytum racemosum is most readily distinguished from G. humile by the dehiscence of the capsules and from G. decipiens by branching habit and by the capsules, which are not as conspicuously flat in G. decipiens. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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Key |
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Source | FNA vol. 10. | FNA vol. 10. | ||||
Parent taxa | Onagraceae > subfam. Onagroideae > tribe Onagreae > Gayophytum | Onagraceae > subfam. Onagroideae > tribe Onagreae > Gayophytum | ||||
Sibling taxa | ||||||
Subordinate taxa | ||||||
Synonyms | G. caesium, G. helleri, G. helleri var. glabrum, G. humile var. hirtellum, G. racemosum var. caesium, G. ramosissimum var. pygmeum | |||||
Name authority | Torrey & A. Gray: Fl. N. Amer. 1: 513. (1840) | Torrey & A. Gray: Fl. N. Amer. 1: 514. (1840) | ||||
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