Key to Onagraceae

View taxon page for Onagraceae

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Sepals persistent after flower; flower parts in (3)4–5(7)s; 

hypanthium 

Structure generally in the shape of a tube, cup, or bowl, derived from the fused lower portions of the perianth and stamens, from which these parts seem to arise, and to which the ovary wall is fused in an inferior ovary (to which the ovary wall is partially fused in a half-inferior ovary; from which the ovary is free in a superior ovary).

0 ..... LUDWIGIA

1' Sepals deciduous after flower (along with other flower parts); flower parts in (2)4s; hypanthium present, often elongate, or if 0 then petals rose-purple to pink, rarely white, or flowers 

bilateral 

Divisible into mirror-image halves in only one way.

2. Stipules present, occasionally deciduous; fruit 

indehiscent 

Not opening inherently to release contents; usually pertaining to fruits.

, bur-like with hooked hairs; flower parts in 2s; stigmas maturing before anthers ..... CIRCAEA

2' Stipules 0; fruit generally 

dehiscent 

Opening at maturity to release contents; usually pertaining to anthers or fruits.

 capsule, rarely indehiscent but not bur-like; flower parts in (3)4s; anthers generally maturing before stigmas

3. Seeds hair-tufted (tufts rarely secondarily lost); sepals 

erect 

Upright; vertically oriented.

; stigmas dry with multicellular papillae

4. Leaves generally 

alternate 

1. Arranged singly, often spirally, along an axis - e.g., one leaf per node. 2. Occurring in different ranks, appearing to be between, not directly above or below, as 'stamens alternate petals'.

; hypanthium 0; petals 

entire 

Having margins that are continuous and smooth (i.e., without teeth, lobes, etc.).

; stamens ± equal, in 1 whorl; pollen blue-gray, grains shed singly ..... CHAMERION

4' Leaves 

opposite 

1. Arranged in pairs along an axis - e.g., two leaves per node. 2. Occurring in the same rank, directly above or below, as 'stamens opposite petals'. 3. Located directly across from.

at least at base; hypanthium 0.3–34 mm; petals notched; stamens in 2 unequal whorls; pollen cream, grains generally shed in 4s ..... EPILOBIUM

3' Seeds not hair-tufted; sepals 

reflexed 

Abruptly bent or curved downward or backward.

; stigmas mainly wet and nonpapillate or with dry unicellular papillae

5. Stigma 4-lobed, dry, papillae unicellular; anthers generally maturing before stigmas ..... CLARKIA

5' Stigma hemispheric, 

peltate 

With the stalk attached toward the middle, not at a margin, of a flat structure such as an indusium, scale, or leaf.

or 4-lobed, wet, papillae 0; anthers not maturing before stigmas

6. Fruit 2-chambered; stems slender, hair-like ..... GAYOPHYTUM

6' Fruit (3)4-chambered; stems generally not slender

7. Seeds with concave and convex sides, concave side with thick 

wing 

1. Thin, flat extension or appendage of a surface or margin. 2. In many members of Fabaceae and in some other groups, each of two lateral petals.

, both sides densely covered with club-shaped hairs; petals white, base yellow ..... CHYLISMIELLA

7' Seeds generally not concave and convex, wing 0, club-shaped hairs 0; petals yellow, purple, red, or white, if white, generally lacking yellow base

8. Ovary tip projection 0.4–18 cm; stem 0

9. Perennial herb; fruit cylindric-ovoid, ± straight or slightly curved, ± angled to nearly smooth, lacking pointed wing near center top of each 

valve 

1. In legumes or capsules opening by longitudinal lines, one of the parts into which the fruit is dehiscent. 2. In anthers, the flap of tissue resulting from dehiscence by a curved line. (e.g., Lauraceae, some Berberidaceae). 3. In Ophioglossaceae, one of the parts into which the sporangium is dehiscent.

, walls generally thin, distended by seeds; sterile projection of ovary persistent with fertile part in fruit, without abscission line at juncture between hypanthium and fertile part of ovary ..... TARAXIA

9' Annual; fruit irregularly obovoid, sharply 4-angled with pointed wing near center top of each valve, thick walled, not distended by seeds; sterile projection of ovary with clear abscission line at juncture between short hypanthium and fertile part of ovary ..... TETRAPTERON

8' Ovary tip projection 0, occasionally ± tapering; stem generally present

10. Stigma 4-lobed ..... OENOTHERA

10' Stigma hemispheric to spheric or 

cylindric 

Elongate, with parallel sides and, at any point, round in transverse section.

11. Seeds in 2 rows per chamber; fruit pedicelled; leaves often ± 

basal 

At or near the base of a plant or plant part. Especially said of leaves clustered near the ground or of a placenta confined to the base of an ovary.

, pinnately lobed with large terminal 

lobe 

1. A major expansion or bulge, such as on the margin of a leaf, sepal, or petal, or on the surface of an ovary. 2. The free tips of otherwise fused structures, such as sepals or petals; larger than teeth.

, occasionally either lateral 

lobes 

1. A major expansion or bulge, such as on the margin of a leaf, sepal, or petal, or on the surface of an ovary. 2. The free tips of otherwise fused structures, such as sepals or petals; larger than teeth.

± reduced or 

leaf 

Organ arising from a stem, generally composed of a stalk (petiole) and a flat, expanded, green, photosynthetic area (blade); distinguished from a leaflet by the presence in its axil of a bud, branch, thorn, or flower; sometimes with lateral, basal appendages (stipules); either simple (toothed, lobed, or dissected but not divided into leaflets) or compound (divided into leaflets).

ovate-cordate and long-petioled; abaxial leaf surface or margin with conspicuous (brown) oil cells ..... CHYLISMIA

11' Seeds in 1 row per chamber; fruit 

sessile 

Without a petiole, peduncle, pedicel, or other kind of stalk.

or occasionally short-pedicelled (Camissonia kernensis); leaves generally not predominately basal, entire to pinnately lobed and if so then terminal lobe not conspicuously larger than lateral; leaf oil cells 0

12. Petals white, pink, or rarely red; flowers night-blooming ..... EREMOTHERA

12' Petals yellow, often with red flecks; flowers day-blooming

13. Flower stems wand-like; leaves pinnately lobed to occasionally entire; petals yellow with red flecks near base; seeds generally with purple spots; hypanthium with lobed disk ..... EULOBUS

13' Flower stems not wand-like; leaves entire to toothed; petals yellow, occasionally with 2 red spots at base, or white; seeds without purple spots; hypanthium without lobed disk

14. Distal stem densely leafy, proximal stem nearly leafless; branches many, slender, 

ascending 

Curving or angling upward from base, or about 30-60 degrees less than vertical or away from axis of attachment.

from base of pl; fruit strongly flattened, straight, 0.5–1 cm ..... NEOHOLMGRENIA

14' Stem generally leafy throughout, branched throughout or with a few basal branches; fruit cylindric to quadrangular, not flattened, often wavy or curled, (0.8)1–6 cm

15. Fruit ± cylindric; plants flower from distal 

nodes 

Position on a stem from which one or more structures (especially leaves, buds, branches, or flowers) arise.

; leaves generally 

linear 

Elongate, with nearly parallel sides; narrower than elliptic or oblong.

to narrowly 

elliptic 

In the shape of a flattened circle or ellipse; wider than linear

; seeds glossy, triangular in ×-section, often < 1 mm ..... CAMISSONIA

15' Fruit 4-angled, at least when dry; plants generally flower from basal nodes; leaves generally narrowly 

lanceolate 

Narrowly elongate, widest in the basal half, often tapered to an acute tip.

, narrowly elliptic or 

ovate 

Egg-shaped (i.e., widest below the middle) in two dimensions (i.e., in one plane), as a leaf.

; seeds dull, often > 1 mm, flattened ..... CAMISSONIOPSIS

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