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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 February 09, 2016.

Citation for the whole project: Jepson Flora Project (eds.) 2016. Jepson eFlora, http://ucjeps.berkeley.edu/IJM.html, accessed on February 09, 2016.


Tetrapteron graciliflorum
click for enlargement
© 2007 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2009 Keir Morse
Tetrapteron graciliflorum
click for enlargement
© 2010 Neal Kramer
Tetrapteron graciliflorum
click for enlargement
© 2009 Keir Morse
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. If the markers are obscured, reload the page [or change window size and reload]. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
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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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CCH collections by month

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