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Tetrapteron graciliflorum
HILL SUN CUP

Higher Taxonomy
Family: OnagraceaeView DescriptionDichotomous Key

Common Name: EVENING-PRIMROSE FAMILY
Habit: Annual to perennial herb (to tree). Leaf: cauline or basal, alternate, opposite, or whorled, generally simple and toothed (to pinnately compound); stipules 0 or generally deciduous. Inflorescence: spike, raceme, panicle, or flowers 1 in axils; bracted. Flower: generally bisexual, generally radial, often opening at either dawn or dusk; hypanthium generally prolonged beyond ovary (measured from ovary tip to sepal base); sepals 4(2--7); petals 4(2--7, rarely 0), often fading darker; stamens 2 × or = sepals in number, anthers 2-chambered, opening lengthwise, pollen interconnected by threads; ovary inferior, chambers generally as many as sepals (sometimes becoming 1), placentas axile or parietal, ovules 1--many per chamber, style 1, stigma 4-lobed (or lobes as many as sepals), club-shaped, spheric, or hemispheric. Fruit: capsule, loculicidal (sometimes berry or indehiscent and nut-like). Seed: sometimes winged or hair-tufted.
Genera In Family: 22 genera, +- 657 species: worldwide, especially western North America; many cultivated (Clarkia, Epilobium, Fuchsia, Oenothera). Note: Gaura moved to Oenothera. Fuchsia magellanica Lam. naturalized in northern California.
eFlora Treatment Author: Warren L. Wagner & Peter C. Hoch, family description, key to genera; treatment of genera by Warren L. Wagner, except as noted
Scientific Editor: Robert Patterson, Bruce G. Baldwin.
Genus: TetrapteronView DescriptionDichotomous Key

Habit: Annual, from taproot, stems rarely present, to 25 mm. Leaf: mostly basal, or cauline on short stems, alternate, broadly sessile or clasping. Inflorescence: flowers 1 in axils of rosette, nodding in bud. Flower: opening at dawn; sepals 4, reflexed in pairs; petals 4, yellow, unspotted, strongly ultraviolet-reflective, fading red-orange; longer stamens opposite sepals, anthers attached near base, pollen grains 3-angled; ovary tip with sterile 0.4--18 cm projection that often breaks off in fruit, with clear abscission line at juncture between short hypanthium and fertile part of ovary, stigma hemispheric, +- = anthers and generally self-pollinated (or > anthers and cross-pollinating). Fruit: irregularly obovoid, sharply 4-angled with pointed wing near center top of each valve, +- sessile, very tardily dehiscent in distal 1/2 only, thick-walled (not distended by seeds), persistent for > 1 year, sessile. Seed: in 2 crowded rows per chamber, obovoid to narrowly obovoid, finely papillate or deeply pitted, tan or brown with dark patches.
Species In Genus: 2 species: California, disjunct in northwestern Nevada, southern Oregon, northern Baja California. Etymology: (Greek: four winged) Note: Incl in Camissonia in TJM (1993).

Tetrapteron graciliflorum (Hook. & Arn.) W.L. Wagner & Hoch
NATIVE
Stem: to 25 mm, not swollen, not peeling. Leaf: 10--98 mm, entire or weakly and minutely serrate. Flower: sepals 4.5--8 mm; petals +- = anthers and generally self-pollinated or exceeding anthers and cross-pollinated; sterile tip of ovary 6--45 mm. Fruit: 4--8 mm, 4-angled (4-winged near tip), leathery, tardily dehiscent. Seed: 1.2--2 mm. Chromosomes: 2n=14.
Ecology: Open or shrubby slopes, generally clay soils, grassland, oak and Joshua-tree woodland; Elevation: < 800 m. Bioregional Distribution: NW, CaR, SNF, GV, CW, WTR; Distribution Outside California: southwestern Oregon, Baja California. Flowering Time: Mar--Apr Note: Generally self-pollinated.
Synonyms: Oenothera graciliflora Hook. & Arn.; Camissonia graciliflora (Hook. & Arn.) P.H. Raven
eFlora Treatment Author: Warren L. Wagner & Peter C. Hoch, family description, key to genera; treatment of genera by Warren L. Wagner
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Citation for this treatment: Warren L. Wagner & Peter C. Hoch, family description, key to genera; treatment of genera by Warren L. Wagner 2016. Tetrapteron graciliflorum, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/cgi-bin/get_IJM.pl?tid=89236, accessed on December 04, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on December 04, 2016.


Tetrapteron graciliflorum
click for enlargement
© 2013 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2007 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2007 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2007 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2005 Keir Morse
Tetrapteron graciliflorum
click for enlargement
© 2007 Neal Kramer

More photos of Tetrapteron graciliflorum in CalPhotos


Geographic subdivisions for Tetrapteron graciliflorum:
NW, CaR, SNF, GV, CW, WTR;
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.