Crotalaria
Crotalaria sagittalis
rabbitbells, rattlebox
arrow crotalaria, arrow-head rattlebox, common rattlebox
erect, ascending, spreading, decumbent, or prostrate, glabrous or pubescent.
erect to decumbent, 4–40 cm, hirsute-pilose.
alternate, palmately compound or unifoliolate;
stipules present or absent, usually persistent, filiform to foliaceous;
petiolate or subsessile;
leaflets 1 or 3[–7], stipels absent, blades 5–150 mm, margins entire, surfaces glabrous or pubescent.
unifoliolate;
stipules sometimes absent, decurrent on mid and distal stems, lanceolate-auriculate or triangular, with 2 distinct, persistent, triangular distal lobes, (3–)5–10 mm or absent (in var. blumeriana);
subsessile;
blade elliptic to oblong or linear-lanceolate, 10–80 mm, length 4–8 times width, surfaces strigose to sparsely rusty-pilose.
(1 or)2–5-flowered, terminal, subterminal, or lateral, 2–6 cm;
bracts persistent, linear-triangular.
(1 or)2–50-flowered, usually terminal or subterminal, leaf-opposed, rarely axillary, racemes [heads or flowers solitary or fascicled];
bracts present, persistent or caducous;
bracteoles present, paired proximal to calyx.
papilionaceous;
calyx usually cylindrical, rarely campanulate or cupulate, lobes 5;
corolla usually yellow, sometimes orangish, rarely white, blue, or lavender, glabrous or hairy outside;
stamens 10, monadelphous;
anthers alternately basifixed on long filaments and dorsifixed on small filaments, dehiscing longitudinally;
style with 1 or 2 lines of hairs adaxially;
stigma terminal, usually bilobed.
calyx broadly cylindrical, 5–8 mm, lobes triangular-lanceolate, glabrous or slightly puberulous to rusty-pilose;
corolla bright yellow, 9–11 mm.
legumes, subsessile to long-stipitate, usually inflated, globose, ovoid to ellipsoid, or cylindrical, dehiscent, often tardily so, glabrous or pubescent.
7–27(–36) × 5–11 mm, glabrous.
1–70, oblique-cordiform to oblong-reniform;
hilar sinus obvious, aril sometimes conspicuous.
= 7, 8.
Crotalaria
Crotalaria sagittalis
Species ca. 600 (15 in the flora).
Crotalaria biflora Linnaeus (native to India) was collected in 1959 as a waif on chrome ore piles in Newport News, Virginia (C. F. Reed 1964). The species is an annual, distinguished as hirsute-villous to subsericeous, stems prostrate, 5–12 cm, leaves sessile, unifoliolate, blades ovate to oblong or oblong-ovate, surfaces villous-hirsute, flowers one or two, on axillary peduncles, and hirsute, ovoid to cylindrical-ovoid legumes.
Crotalaria alata Buchanan-Hamilton ex D. Don (native to Himalayan Asia) was collected in 1939 as an escape in Gainesville, Florida (W. A. Murrill s.n., MO); subsequently, it has not been recorded in the flora area. The species is perennial, distinguished as hirsute to strigose-hirsute, stems erect, 10–20 cm, leaves unifoliolate, blades lanceolate to elliptic-lanceolate or elliptic, stipules decurrent, forming wings on internodes, and apically bilobed, flowers in terminal and axillary racemes, 4–10 cm, and legumes glabrous.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Varieties 2 (2 in the flora).
(Discussion copyrighted by Flora of North America; reprinted with permission.)
1. Leaves 3-foliolate. | → 2 |
2. Leaflet blades 5–15(–35) mm; legumes 7–20 mm. | → 3 |
3. Stems mostly decumbent to prostrate, minutely and sparsely strigillose; legumes. | C. pumila |
3. Stems erect to decumbent, loosely strigose to strigose-hirsute; legumes 7–10 mm. | C. virgulata |
2. Leaflet blades (10–)20–130(–180) mm; legumes (16–)18–70 mm. | → 4 |
4. Leaflet blades linear to linear-lanceolate, elliptic-lanceolate, or lanceolate, lengths 5–10 times widths. | → 5 |
5. Racemes 12–26(–40)-flowered; corollas 8–11 mm; legumes 4–6 mm diam. | C. lanceolata |
5. Racemes 4–12-flowered; corollas 18–20 mm; legumes (10–)15–20 mm diam. | C. ochroleuca |
4. Leaflet blades obovate, ovate, elliptic-obovate, elliptic-oblanceolate, elliptic, elliptic-lanceolate, or spatulate-obovate, lengths 1.3–4.5 times widths. | → 6 |
6. Stipules absent; leaflet blades elliptic to elliptic-lanceolate, or elliptic-oblanceolate, 40–100(–140) mm, lengths 3–4.5 times widths; calyces basally truncate and deflexed against pedicels. | C. trichotoma |
6. Stipules usually present (persistent or caducous); leaflet blades elliptic, ovate, obovate, elliptic-obovate, or spatulate-obovate, (10–)20–70 mm, lengths 1.3–2.5 times widths; calyces sometimes basally truncate, not deflexed against pedicels. | → 7 |
7. Legumes 5–6 mm diam., slightly to conspicuously curved, minutely puberulent to glabrate; stems strigose; leaflet surfaces strigillose abaxially, glabrous adaxially. | C. pallida |
7. Legumes 10–15 mm diam., straight, villous-hirsute to hispid-hirsute; stems hirsute-villous to strigose-hirsute; leaflet surfaces glabrous or hairy on abaxial midvein. | C. incana |
1. Leaves unifoliolate. | → 8 |
8. Corollas usually blue to lavender, sometimes white or pale yellow tinged blue; stipules present, often encircling nodes. | C. verrucosa |
8. Corollas bright yellow; stipules present and not encircling nodes, or absent. | → 9 |
9. Stipules decurrent on mid and distal stems. | → 10 |
10. Herbs annual; stems erect to decumbent, hirsute-pilose; leaflet blade lengths 4–8 times widths. | C. sagittalis |
10. Herbs perennial; stems decumbent, prostrate, ascending, or erect, strigose or strigose-sericeous to hirsute-villous; leaflet blade lengths 1–12 times widths. | → 11 |
11. Leaflet blades linear-lanceolate, linear-oblanceolate, linear, oblong, or elliptic (narrower distally), lengths (2–)4–10 times widths, surfaces glabrous adaxially; stems erect to ascending. | C. purshii |
11. Leaflet blades broadly elliptic to elliptic-ovate, ovate, broadly lanceolate, linear, linear-lanceolate, or obovate-oblanceolate, lengths 1–12 times widths, surfaces strigose to strigose-hirsute adaxially; stems prostrate to decumbent or ascending. | C. rotundifolia |
9. Stipules, when present, not decurrent on stems. | → 12 |
12. Herbs perennial; stipules absent; leaflet blades (5–)8–19 mm; stems 2–10 cm; corollas 8–9 mm. | C. avonensis |
12. Herbs annual; stipules usually present; leaflet blades 30–150 mm; stems 30–200(–400) cm; corollas 15–25 mm. | → 13 |
13. Stipules ovate to ovate-lanceolate, 4–7 mm; floral bracts 5–8 mm, persistent; stems glabrous. | C. spectabilis |
13. Stipules, when present, filiform or setaceous, 1–2 mm; floral bracts 2–5 mm, persistent or caducous; stems strigose or strigose-sericeous. | → 14 |
14. Leaflet blades obovate to spatulate or oblanceolate, 30–80 mm, lengths. | → 2 |
2. 2–3(–4) times widths; stems 30–90 cm. | C. retusa |
14. Leaflet blades linear-elliptic to oblong, 50–150 mm, lengths 2.5–4 times widths; stems 100–200(–400) cm. | C. juncea |
1. Stems 10–40 cm, erect; stipules prominent; legumes 10–27(–36) mm. | var. sagittalis |
1. Stems 4–10 cm, erect to decumbent; stipules reduced or absent; legumes 7–15 mm. | var. blumeriana |
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