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Brassicaceae
See list of 42 genera in this familyMatthiola incana (L.) Ait. was reported from VT by Atwood et al. (1973); however, the specimen was collected from a cultivated plant (Blanchard collection at HNH). Reference: Rollins (1993).
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1a. Fruit a silicle (i.e., fruit up to 3 times as long as wide), elliptic or oblong to suborbicular or obtriangular in outline, sometimes with a notch or sinus at the base and/or apex [Figs. 506,521,531]
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2a. Silicle indehiscent or tardily dehiscent, containing 1–4 (–5) seeds, inflated, corky, or spongy at least between the seeds (firm in Neslia)
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3a. Plants pubescent in part with branched hairs; petals 1–2.5 mm long
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4a. Silicle evidently reticulate-textured, glabrous, tipped by the slender, persistent, uncurved style; petals yellow, 2–2.5 mm long; leaves auriculate clasping
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4b. Silicle not reticulate-textured, pubescent with both branched and unbranched, white hairs, with an apical beak that curves away from the inflorescence rachis; petals white, 1–1.3 mm long; leaves petiolate or sessile, but not clasping
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3b. Plants glabrous or pubescent entirely with unbranched hairs; petals 3–20 mm long
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5a. Silicle 2.5–3 mm long; leaves auriculate-clasping; plants perennial (in part)
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5b. Silicle 6–60 mm long; leaves not auriculate-clasping; plants annual
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6a. Petals 15–20 mm long; silicle 30–60 mm long; plants from a fleshy, elongated taproot (in part)
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6b. Petals 5–10 mm long, sometimes reduced in Cakile and bristle-like; silicle 6–25 mm long; plants not from a fleshy, enlarged taproot
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7a. Petals pale purple to purple or white; leaf blades glabrous; upper segment of fruit lanceoloid to ovoid, without a terminal beak or with a stocky beak [Fig. 510] (in part)
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7b. Petals yellow; leaf blades hirsute; upper segment of fruit subglobose, terminated by a slender beak 1–4 mm long (in part)
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2b. Silicle dehiscent, containing 2–many seeds, appearing inflated or not
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8a. Silicle compressed at right angles to the septum, the septum therefore much narrower than the width of the fruit [Fig. 531]
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9a. Leaves subulate, not flat, all basal [Fig. 530]; plants aquatic, frequently in submerged populations that become emergent as water levels decline
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9b. Leaves not subulate, definitely flat, not confined to the base of the plant except in Teesdalia; plants terrestrial weeds
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10a. Silicle with 2 seeds
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11b. Outer two petals larger than the inner two; silicle with a long style projecting from the prominently retuse apex
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10b. Silicle with 4 or more seeds
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12a. Outer two petal larger than the inner two; median filaments with a white scale at the base; plants scapose
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12b. Petals all of similar size; median filaments without a basal scale; plants with leafy stems
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13a. Silicle oval to orbicular to outline, wing-margined, rounded to broad-cuneate at the base, conspicuously retuse at the apex [Fig. 531]; plants glabrous or pubescent with unbranched hairs
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13b. Silicle obtriangular to obtriangular-cordate in outline, not wing-margined, cuneate at the base, convex to slightly concave at the apex; plants pubescent with branched hairs
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8b. Silicle either not compressed or compressed parallel to the septum, in either case the septum as wide as the fruit
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14a. Silicle thin and flat, 20–35 mm wide, borne on a gynophore longer than 10 mm [Fig. 523]; stem leaf blades ovate to deltate; petals blue-purple
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14b. Silicle compressed to plump, narrower than 6 mm, either sessile at the end of the pedicel or on a very short gynophore; stem leaf blades usually narrower or absent; petals white or yellow (sometimes tinged with purple in Lobularia)
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15b. Petals entire at the apex or slightly retuse (deeply notched in Draba verna, a small, scapose annual); fruiting pedicels spreading to ascending; seeds unwinged (winged in Aurinia)
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16a. Silicle irregularly tuberculate, often asymmetrical (i.e., one locule larger than the other); plants frequently with sessile, tubercle-like glands on the leaf blades
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16b. Silicle not tuberculate, usually symmetrical; plants without tubercle- like glands
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17a. Silicle conspicuously compressed; pubescence, at least in part, of branched hairs
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18a. Petals yellow; seeds winged all around
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18b. Petals cream to white; seed unwinged
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19a. Flower-bearing stems arising from a basal rosette of leaves; silicle lanceolate to narrow-oblong or oblong in outline, 4–20 mm long (in part)
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19b. Flower-bearing stems lacking a conspicuous basal rosette; silicle broad-ovate or broad-obovate to orbicular in outline, 2–4 mm long
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20a. Plants pubescent with stellate-branched hairs; silicle with a thin, wing-like margin, with seeds aligned in 2 rows in each locule; fruiting pedicels 2–6 mm long
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20b. Plants pubescent with 2-pronged hairs; silicle lacking a thin margin, with seeds aligned in 1 row in each locule; fruiting pedicels 5–10 mm long
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17b. Silicle with definite, convex valves, scarcely compressed if at all; pubescence, if present, of unbranched hairs (except Camelina with some branched hairs)
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21a. Plants pubescent with both unbranched and branched hairs (sometimes subglabrous in C. sativa); leaves conspicuously auriculate-clasping the stem; each valve of the silicle with a thin but visible and often sinuous midnerve
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21b. Plants glabrous or pubescent with unbranched hairs; leaves narrowed to the base or auriculate-clasping; each valve of the silicle without a midnerve or with an obscure midnerve
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22a. Petals white; leaf blades simple; seeds rarely maturing; silicle with a persistent style tip 0.3 mm long
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1b. Fruit a silique (i.e., fruit greater than 3 times as long as wide), narrow-oblong to linear in outline, without a notch or sinus at the base or apex [Figs. 504,507,524]
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23a. Silique indehiscent, separating at maturity into 1-seeded segments, prominently corky or spongy, at least between the seeds, or indurate and cross-septate in Chorispora [Figs. 510,524]
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24a. Stems and axis of inflorescence conspicuously stipitate-glandular; seeds embedded in cavities of the septum
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24b. Stems and axis of inflorescence lacking stipitate glands; seeds not embedded in cavities of the septum
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25a. Petals 15–20 mm long; siliques 40–80 mm long, with 4–12 seeds [Fig. 524]; fruiting pedicels 10–25 mm long (in part)
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25b. Petals 5–10 mm long, sometimes reduced in Cakile and bristle-like; siliques 6–25 mm long, with 1–3 seeds; fruiting pedicels 1.5–8 mm long
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26a. Petals pale purple to purple or white; leaf blades glabrous; upper segment of fruit lanceoloid to ovoid, without a prominent, slender beak (in part)
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26b. Petals yellow; leaf blades hirsute; upper segment of fruit subglobose, terminated by a prominent, slender beak 1–4 mm long (in part)
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23b. Silique longitudinally dehiscent (with an apical, indehiscent beak in Brassica, Eruca, and Sinapis), the open valves revealing the seeds and septum, generally not corky or spongy, lacking cross-septa [Figs. 504,509,514]
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27a. Leaf blades simple, entire or toothed, but lacking pronounced lobes (except for basal lobes in cordate- or sagittate-shaped leaf blades)
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29a. Middle stem leaves sessile and sagittate- or auriculate-clasping
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30a. Pubescence of basal leaves, when present, comprised entirely of unbranched hairs or, in part, of short-stalked, 2- to 4 (–7)-rayed hairs, the stalks mostly 0.01–0.06 mm long [Fig. 517]; siliques 1–2.5 mm wide (in part)
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30b. Pubescence of basal leaves comprised, in part, of long-stalked, 2- to 4-rayed hairs, the stalks mostly 0.12–0.6 mm long [Fig. 518]; siliques 0.8–1.3 mm wide
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31a. Petals pale yellow; outer sepals not saccate at base; middle and upper stem leaves glabrous and glaucous; siliques terete
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31b. Petals white, sometimes tinged with pink; outer sepals somewhat saccate at base; middle and upper stem leaves pubescent, not glaucous; siliques compressed (in part)
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29b. Middle stem leaves narrowed to base, sometimes ± shortly petiolate [Fig. 507]
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32a. Petals yellow; siliques pubescent with branched hairs; some of the hairs on the leaf blades malpighiaceous (i.e., hairs 2-pronged, less frequently 3-pronged, mesifixed and appressed to the surface) (in part)
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32b. Petals white or pink to purple; siliques glabrous or pubescent in some Draba; hairs of the leaf blades unbranched or branched, but none of them malpighiaceous (except in the rare introduction Arabis procurrens, a species with compressed siliques)
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33a. Petals 18–25 mm long, white or pink to purple; compound hairs all forked (i.e., with a stalk and 2 ascending branches)
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33b. Petals 2–10 mm long, usually white (infrequently pink or rose- purple); compound hairs with 2 or more ascending to spreading branches (i.e., compound hairs not uniformly forked with ascending branches)
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34a. Siliques narrow-lanceolate or narrow-oblong to ovate or obovate in outline, 4–20 (–22) mm long, up to 5 times as long as wide; seeds aligned in 2 rows in each locule (in part)
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34b. Siliques linear in outline, 10–100 mm long, more than 5 times as long as wide; seeds aligned in 1 row in each locule
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35a. Siliques often torulose; fruiting pedicels (1–) 1.5–6 (–8) mm long
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35b. Siliques scarcely, if at all, constricted between the seeds; fruiting pedicels 5–15 mm long
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36a. Plants 3–10 dm tall, usually with unbranched stems; siliques 2–3.5 mm wide; seeds winged (in part)
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36b. Plants 0.8–4 dm tall, frequently branched at the base or with stolons, producing multiple upright stems; siliques 0.8–1.5 mm wide; seeds without wings (winged in Arabis procurrens)
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37a. Primary leaf blades usually with some form of dentition or lobing; siliques 0.8–1 mm wide; petals 2–8 (–10) mm long (in part)
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37b. Primary leaf blades usually entire; siliques 1–1.5 mm wide; petals 8–10 mm long; (in part)
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28b. Plants glabrous or pubescent entirely with unbranched hairs
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38a. Stem leaves conspicuously cordate- or sagittate-clasping at the base
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39a. Petals 6–25 (–30) mm long, narrowed to a distinct claw; siliques 2–5 mm wide (in part)
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39b. Petals 3–12 mm long, narrowed to the base, but usually without a distinct claw; siliques 1–2.5 (–3.5) mm wide
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40a. Plants annual, with entire leaf blades; petals yellow to yellow-white, 7–12 mm long; siliques quadrangular in cross-section; seeds without wings
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40b. Plants biennial or perennial, with at least the lower leaf blades toothed to pinnatifid (rarely all entire); petals 3–10 mm long, white (infrequently yellow-white or light purple); siliques compressed; seeds with a partly or completely encircling wing-margin usually wider than 0.2 mm (in part)
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38b. Stem leaves not clasping at the base [Fig. 507]
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41a. At least the basal leaf blades triangular to suborbicular or reniform, broad-rounded to cordate at the base
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42a. Basal leaf blades entire or undulate-margined, the stem leaf blades entire, remotely toothed, or lobed; siliques compressed; septum bordered by a thin wing-like replum set perpendicular to the plane of the septum, therefore, the septum and replum combined are I-beam-shaped in cross-section (in part)
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42b. Basal and stem leaf blades prominently dentate; siliques somewhat 4-angled in cross-section; replum essentially the same thickness as the septum, the septum and replum combined flat in cross-section
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41b. Leaf blades broad-linear or oblanceolate to elliptic, ovate, or obovate, narrowed to the base
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43a. Sepals spreading to reflexed [Fig. 527]; siliques with a prominent, apical, indehiscent, conical beak 10–12 mm long (in part)
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43b. Sepals erect to ascending; siliques without an apical, indehiscent beak or the beak present and only 1–5 (–6) mm long
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44a. Siliques quadrangular, erect (i.e., ± appressed to the axis of the inflorescence); petals narrowed to a distinct claw (in part)
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44b. Siliques terete to compressed, spreading to erect; petals narrowed to the base, with or without a distinct claw
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45a. Petals yellow; seeds aligned in 2 rows in each locule (in part)
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45b. Petals white to pink or light purple; seeds aligned in 1 row in each locule
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46a. Siliques 15–35 mm long; septum bordered by a thin wing-like replum set perpendicular to the plane of the septum, therefore, the septum and replum combined are I-beam-shaped in cross-section; dwarf alpine plants 2–10 cm tall (in part)
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46b. Siliques 40–100 mm long; replum essentially the same thickness as the septum, the septum and replum combined flat in cross-section; herbs of forests, cliffs, and talus, 10–90 cm tall
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47a. Slender plants 10–40 cm tall, frequently branched at the base, producing multiple upright stems; siliques 0.8–1 mm wide; seeds without wings (in part)
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47b. Stouter plants 30–100 cm tall, usually with unbranched stems; siliques 2–3.5 mm wide; seeds winged (in part)
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27b. At least the lower leaf blades lobed or divided
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48a. Principal leaf blades palmately lobed or palmately divided into 3–5 segments; stem gradually narrowing at base to a fragile junction with a swollen, fleshy rhizome (in part)
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48b. Principal leaves pinnately lobed or pinnately divided; stems in most genera arising from taproots or fibrous roots, when arising from rhizomes the stem widest at the base and narrowing upward and/or continuous with the rhizome
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49a. Plants pubescent, at least in part, with branched hairs
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50a. Inflorescence leafy-bracteate, most or all of the pedicels subtended by bracts (in part)
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50b. Inflorescence not bracteate, only the lower pedicels, if any, subtended by bracts
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51a. Leaf blades 1–3 times pinnately divided; branched hairs dendritic
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51b. Leaf blades pinnately lobed; branched hairs malpighiaceous (i.e., hairs 2-pronged, less frequently 3-pronged, mesifixed and appressed to the surface) (in part)
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49b. Plants glabrous or pubescent entirely with unbranched hairs
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52a. Stem leaves sessile and auriculate-clasping (only the emergent leaves in Nastustium sometimes with auricles at the base of the petiole) [Figs. 505,514]
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53a. Petals white and 2–3 mm long or absent; septum bordered by a thin wing-like replum set perpendicular to the plane of the septum, therefore, the septum and replum combined are I-beam-shaped in cross-section (in part)
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53b. Petals yellow, or white in Nasturtium and some Boechera, but then 3–7 mm long; replum essentially the same thickness as the septum, the septum and replum combined flat in cross-section
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54a. Leaves with pinnately compound blades, the leaflets often petiolulate; plants aquatic, with submersed or floating stems (or prostrate on mud as water levels decline), freely rooting from the nodes (in part)
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54b. Middle and upper stem leaves with toothed to pinnately lobed, but not compound, leaf blades, the leaflets connected to each other by at least a wing of tissue along the leaf rachis; plants terrestrial or of wetlands, the stems upright or sometimes prostrate, not or only sparingly rooting from the lower nodes
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55a. Petals white to yellow-white; seeds with an encircling wing; siliques wide-spreading to recurved at maturity [Fig. 507] (in part)
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55b. Petals yellow; seeds without wings; siliques ascending to spreading
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56a. Siliques terminated by an indehiscent beak 7–15 mm long; seeds subglobose (in part)
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56b. Siliques without an apical, indehiscent beak, tipped only by a persistent style up to 3 mm long if at all; seeds oblong to quadrate or cordiform (rarely maturing in some Rorippa)
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57a. Siliques 3–15 (–20) mm long (rarely maturing in some Rorippa), with seeds aligned in 2 rows in each locule; valves of silique ± nervelss; stems terete (in part)
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57b. Siliques 10–80 mm long, with seeds aligned in 1 row in each locule; valves of silique with a prominent midnerve; stems angled
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52b. Stem leaves petiolate or sessile, but not clasping the stem
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58a. Siliques flat or strongly compressed
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59a. Petals yellow in life; seeds aligned in 2 rows in each locule (in part)
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59b. Petals white to pink to purple; seeds aligned in 1 row in each locule
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60b. Lower leaf blades pinnately lobed to dentate; replum essentially the same thickness as the septum, the septum and replum combined flat in cross-section (in part)
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58b. Siliques terete or quadrangular in cross-section, each valve strongly convex
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61a. Seeds aligned in 2 rows in each locule
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62a. Silique terminated by a broad, flat, indehiscent beak 5–12 mm long that is ½ to fully as long as the valves; petals white to white-yellow with red-purple veins
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62b. Silque without an apical beak or with a short beak 1–3 mm long that is much shorter than the valves; petals entirely white or yellow
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63a. Petals white; leaves with pinnately compound blades, the leaflets often petiolulate; plants aquatic, with submersed or floating stems (or prostrate on mud as water levels decline), freely rooting from the nodes (in part)
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63b. Petals yellow or absent; middle and upper stem leaves with toothed to pinnately lobed, but not compound, leaf blades, the leaflets connected to each other by at least a wing of tissue along the leaf rachis; plants terrestrial or of wetlands, the stems upright or sometimes prostrate, not or only sparingly rooting from the lower nodes
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64a. Inflorescence leafy-bracteate, most or all of the pedicels subtended by bracts (in part)
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64b. Inflorescence not bracteate, only the lower pedicels, if any, subtended by bracts
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65a. Siliques 3–15 (–20) mm long, the valves of silique ± nerveless; fruiting pedicels 0.5–14 mm long (in part)
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65b. Siliques 20–45 mm long, the valves with a prominent midnerve; fruiting pedicels (6–) 10–30 (–35) mm long (in part)
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61b. Seeds aligned in 1 row in each locule
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66a. Petals white; leaves with pinnately compound blades, the leaflets often petiolulate; plants aquatic, with submersed or floating stems (or prostrate on mud as water levels decline), freely rooting from the nodes (in part)
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66b. Petals pale yellow to yellow in life (sometimes white-yellow in the cultivated Brassica oleracea); middle and upper stem leaves with toothed to pinnately lobed, but not compound, leaf blades, the leaflets connected to each other by at least a wing of tissue along the leaf rachis (those of Sisymbrium altissimum with linear to filiform segments that often lack connecting tissue along the rachis); plants primarily terrestrial weeds with upright stems that do not root from the nodes
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67a. Seeds subglobose; silique tipped by an indehiscent beak 1–30 mm long
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68a. Each valve of the silique with 1 prominent nerve; indehiscent beak of fruit terete or angled, without seeds (very rarely with 1 or 2 seeds); sepals erect to ascending (in part)
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68b. Each valve of the silique with 3 prominent nerves; indehiscent beak of fruit compressed or compressed-quadrangular, often containing 1 (–3) seeds; sepals spreading to reflexed [Fig. 527] (in part)
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67b. Seeds obloid or ovoid; silique tipped by the persistent style up to 3 mm long
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69a. Inflorescence not bracteate, only the lower pedicels, if any, subtended by bracts [Fig. 528]; valves of silique with 3 nerves
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69b. Inflorescence leafy-bracteate, most or all of the pedicels subtended by bracts; valves of silique with 1 nerve
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Each photo represents one genus in this family.