OregonFlora: Brassica rapa vs. Brassicaceae

	Brassica rapa	Brassicaceae
	field mustard, turnip	mustard family
Habit	Plants annual or biennial, glabrous or sparsely pubescent basally, rarely glaucous.	Herbs, rarely woody subshrubs or shrubs annual, biennial, or perennial; taprooted or with caudices, sometimes rhizomatous; trichomes unicellular, simple, 2–many-rayed, stellate, dendritic, or malpighiaceous; stalked or sessile; multicellular glands with uniseriate or multiseriate stalks present or absent.
Stems	3–12(19) dm.	leafy or leafless, sometimes absent.
Leaves		basal and/or cauline; simple or compound; margins entire or variously divided, petiolate or sessile; without stipules.
Basal leaves	and lowermost cauline (5)10–40(60) × 3–10 (20) cm; margins entire, dentate, or pinnatisect, with terminal lobes larger than 1–6 lateral lobes on each side, petiolate.
Inflorescences	fruiting pedicels ascending to divaricate; (5)10–25(30) mm.	racemes; corymbs, or panicles, sometimes flowers solitary from a basal rosette.
Flowers	sepals oblong; (3)4–6.5(8) mm, ascending; petals obovate; (5)7–10(13) × (2.5)3–6(7) mm, bright yellow, rarely pale or whitish yellow; claws 3–7 mm; anthers oblong, 1.5–2 mm; filaments 4–6(7) mm; lateral curved at base; styles obsolete.	bisexual, hypogynous, radially or rarely bilaterally symmetric; sepals 4; in 2 decussate pairs, usually free; petals 4, forming a cross, rarely absent; stamens (2 or 4)6; in 2 whorls, tetradynamous, rarely equal in length or in 3 pairs of unequal length; median filaments free or rarely united; anthers dithecal, dehiscing by longitudinal slits; pollen 3(10)-colpate, trinucleate; pistils 1, 2-carpelled; ovaries superior; placentation parietal or rarely apical; septa complete, perforated, or lacking; styles 1; stigmas entire or 2-lobed, nectar glands receptacular.
Fruits	divaricate to ascending; terete; (2)3–8(11) cm × 2–4(5) mm, valvular segments (1.3)2–5(7.5) cm, 8–15-seeded per locule; valves with prominent midveins; terminal segments conical; (0.3)1–2.5(3.5) cm; seedless or rarely 1-seeded, sessile.	typically 2-valved capsules (siliques or silicles), dehiscent or indehiscent; terete, 4-angled, flattened parallel to or perpendicular to septum; replums rounded or rarely winged.
Seeds	1–1.8 mm in diameter.	uniseriately or biseriately arranged in each locule, rarely aseriate, mucilaginous or not when wetted, winged or wingless; cotyledons incumbent or accumbent, conduplicate.
Upper cauline leaves	ovate to lanceolate, 2–8(12) × 0.8–3 cm, bases amplexicaul or auriculate, sessile.
2n	=20.

	Brassica rapa	Brassicaceae
Distribution	[WildflowerSearch map] [BONAP county map]	[BONAP county map]
Discussion	Abandoned fields, roadsides, disturbed areas, gardens. Flowering Apr–Oct. 0–1500 m. BW, Casc, Col, CR, Est, Lava, Sisk, WV. CA, ID, NV, WA; worldwide. Exotic. Brassica rapa includes many cultivars. These are recognized as varieties or subspecies, including turnip (ssp. rapa), Chinese mustard or bok choy (ssp. chinensis), and Chinese cabbage or petsai (ssp. pekinensis).	Cosmopolitan. 340 genera; 59 genera treated in Flora. This family includes many economically important crop plants that are grown as vegetables, sources of vegetable oils (canola), or condiments (table mustard, horseradish, wasabi), or ornamentals. It also includes some 130 species of weeds, including Arabidopsis thaliana, a model organism in experimental and molecular biology. The limits of Brassicaceae (Cruciferae) have not changed in the past two centuries because of characteristic floral and fruit morphology. Generic delimitation within the family is often difficult because of the reliance on fruit characters to separate genera. The ovule number per ovary is a taxonomically important character, which can easily be determined by counting the number of seeds and aborted ovules in the mature fruit. The use of seed number alone may be taxonomically unreliable because many ovules fail to develop into seeds, especially late in the season due to the lack of sufficient pollen.
Source	Flora of Oregon, volume 2, page 459 Ihsan Al-Shehbaz	Flora of Oregon, volume 2, page 434
Sibling taxa	B. elongata, B. juncea, B. napus, B. nigra, B. oleracea
Synonyms	Brassica campestris
Web links	Local floras: BC, CA, OR, WA Local Web sites: CalFlora, CalPhotos, Flora NW, PNW Herbaria, Turner Photog. WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	Local floras: OR Local Web sites: Flora NW, PNW Herbaria WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Brassicaceae

field mustard, turnip

mustard family

Habit

Plants annual or biennial, glabrous or sparsely pubescent basally, rarely glaucous.

Herbs, rarely woody subshrubs or shrubs annual, biennial, or perennial; taprooted or with caudices, sometimes rhizomatous; trichomes unicellular, simple, 2–many-rayed, stellate, dendritic, or malpighiaceous; stalked or sessile; multicellular glands with uniseriate or multiseriate stalks present or absent.

Stems

3–12(19) dm.

leafy or leafless, sometimes absent.

Leaves

basal and/or cauline; simple or compound;

margins entire or variously divided, petiolate or sessile; without stipules.

Basal leaves

and lowermost cauline (5)10–40(60) × 3–10 (20) cm;

margins entire, dentate, or pinnatisect, with terminal lobes larger than 1–6 lateral lobes on each side, petiolate.

Inflorescences

fruiting pedicels ascending to divaricate; (5)10–25(30) mm.

racemes; corymbs, or panicles, sometimes flowers solitary from a basal rosette.

Flowers

sepals oblong; (3)4–6.5(8) mm, ascending;

petals obovate; (5)7–10(13) × (2.5)3–6(7) mm, bright yellow, rarely pale or whitish yellow;

claws 3–7 mm;

anthers oblong, 1.5–2 mm;

filaments 4–6(7) mm;

lateral curved at base;

styles obsolete.

bisexual, hypogynous, radially or rarely bilaterally symmetric;

sepals 4; in 2 decussate pairs, usually free;

petals 4, forming a cross, rarely absent;

stamens (2 or 4)6; in 2 whorls, tetradynamous, rarely equal in length or in 3 pairs of unequal length;

median filaments free or rarely united;

anthers dithecal, dehiscing by longitudinal slits;

pollen 3(10)-colpate, trinucleate;

pistils 1, 2-carpelled;

ovaries superior;

placentation parietal or rarely apical;

septa complete, perforated, or lacking;

styles 1;

stigmas entire or 2-lobed, nectar glands receptacular.

Fruits

divaricate to ascending; terete; (2)3–8(11) cm × 2–4(5) mm, valvular segments (1.3)2–5(7.5) cm, 8–15-seeded per locule;

valves with prominent midveins; terminal segments conical; (0.3)1–2.5(3.5) cm; seedless or rarely 1-seeded, sessile.

typically 2-valved capsules (siliques or silicles), dehiscent or indehiscent; terete, 4-angled, flattened parallel to or perpendicular to septum; replums rounded or rarely winged.

Seeds

1–1.8 mm in diameter.

uniseriately or biseriately arranged in each locule, rarely aseriate, mucilaginous or not when wetted, winged or wingless;

cotyledons incumbent or accumbent, conduplicate.

Upper cauline leaves

ovate to lanceolate, 2–8(12) × 0.8–3 cm, bases amplexicaul or auriculate, sessile.

=20.

Brassica rapa

Brassicaceae

Distribution

[WildflowerSearch map]

[BONAP county map]

Discussion

Abandoned fields, roadsides, disturbed areas, gardens. Flowering Apr–Oct. 0–1500 m. BW, Casc, Col, CR, Est, Lava, Sisk, WV. CA, ID, NV, WA; worldwide. Exotic.

Brassica rapa includes many cultivars. These are recognized as varieties or subspecies, including turnip (ssp. rapa), Chinese mustard or bok choy (ssp. chinensis), and Chinese cabbage or petsai (ssp. pekinensis).

Cosmopolitan. 340 genera; 59 genera treated in Flora.

This family includes many economically important crop plants that are grown as vegetables, sources of vegetable oils (canola), or condiments (table mustard, horseradish, wasabi), or ornamentals. It also includes some 130 species of weeds, including Arabidopsis thaliana, a model organism in experimental and molecular biology. The limits of Brassicaceae (Cruciferae) have not changed in the past two centuries because of characteristic floral and fruit morphology. Generic delimitation within the family is often difficult because of the reliance on fruit characters to separate genera. The ovule number per ovary is a taxonomically important character, which can easily be determined by counting the number of seeds and aborted ovules in the mature fruit. The use of seed number alone may be taxonomically unreliable because many ovules fail to develop into seeds, especially late in the season due to the lack of sufficient pollen.

Source

Flora of Oregon, volume 2, page 459
Ihsan Al-Shehbaz

Flora of Oregon, volume 2, page 434

Sibling taxa

B. elongata, B. juncea, B. napus, B. nigra, B. oleracea

Synonyms

Brassica campestris

Web links