FNA: Jatropha canescens vs. Jatropha cuneata

	Jatropha canescens	Jatropha cuneata
	Arizona nettlespurge, sangre de drago	leatherplant, limberbush, physicnut, sangre de drago
Habit	Shrubs, to 1.2–2.5 m, dioecious.	Shrubs, to 2 m, dioecious.
Stems	erect, grayish white, branched from base, woody-succulent, canescent; short shoots common; latex watery, cloudy-whitish.	spreading, yellow to yellow-brown [gray], much-branched, woody-succulent, glabrous; short shoots common; latex watery, yellow in young shoots, red in older shoots.
Leaves	deciduous, mostly ± evenly distributed on long shoots, few on short shoots; stipules absent; petiole 1.3–3 cm, not stipitate-glandular; blade cordate to broadly ovate, 2.2–3.5 × 1.6–3 cm, unlobed or shallowly 3-lobed, base truncate-cordate, margins entire, apex rounded, ± coriaceous, abaxial surface canescent, adaxial surface sparingly hairy; venation pinnate (palmate if lobed).	deciduous, usually fascicled on short shoots; stipules absent; petiole 0(–0.2) cm, not stipitate-glandular; blade obovate-spatulate, 0.7–1.9 × 0.3–0.9 cm, unlobed (shallowly 3-lobed on active shoots), base attenuate, margins entire, apex usually rounded, sometimes emarginate, coriaceous, surfaces glabrous; venation pinnate (palmate if lobed).
Inflorescences	terminal on branches or on short shoots, staminate cymes, pistillate fascicles, or flowers solitary; peduncle 1–2.6 cm; bracts 1–2.5 mm, margins entire, sparsely hairy.	on short shoots, cymes or flowers solitary; peduncle 0.4–0.6 cm; bracts 0.4–1 mm, margins entire, glabrous.
Pedicels	2–3 mm.	1–4(–6.5) mm.
Staminate flowers	sepals connate to 1/4 length, lanceolate, 2–2.5 × 0.5–0.8 mm, margins entire, apex acute, canescent abaxially, glabrous or sparingly hairy adaxially; corolla grayish white, sometimes pinkish abaxially, subglobose-urceolate, petals connate 3/4–4/5 length, 5–8 × 1–2 mm, surfaces sparingly hairy; stamens 10 in 2 whorls (5 + 5); filaments of outer whorl connate 1/2 length, of inner whorl connate 1/4 length, outer whorl 2–3 mm, whorl series 4–5 mm.	sepals connate basally, ovate-lanceolate, 2.5–4 × 0.6–1 mm, margins entire, apex acute, surfaces glabrous; corolla white, tubular-urceolate, petals connate most of length, 4–6 × 1.3–2 mm, surfaces glabrous; stamens 10 in 2 whorls (5 + 5); filaments of both whorls connate almost to top, outer whorl 1–2.5 mm, inner series 2.5–4 mm.
Pistillate flowers	resembling staminate, but sepals connate only at base, 3–3.5 × 1.5–2 mm; petals connate 1/2–3/4 length, 8–11 × 3–5 mm; carpels 2[–3]; styles connate 3/4 their lengths, 2–5 mm.	resembling staminate, but sepals distinct, 1.5–3 × 0.5–1 mm; petals 4–4.5 × 1–1.5 mm; carpel 1; styles 0.5–1 mm.
Capsules	compressed ellipsoidal, 1.2–1.5 × 2–2.5 cm, 2-lobed [ellipsoidal, 3-lobed], tardily dehiscent.	spheric, 0.9–1.1 × 0.9–1.1 cm, tardily dehiscent.
Seeds	solid brown, subspheric, 9–12 mm; caruncle absent.	solid dark to golden brown, spheric, 10 × 10 mm; caruncle absent.
2n	= 22 (Mexico).	= 44 (Mexico).

	Jatropha canescens	Jatropha cuneata
Phenology	Flowering and fruiting late spring(–summer).	Flowering and fruiting late spring–summer.
Habitat	Sandy washes, sand dunes.	Dry rocky limestone mesas, sandy areas, bajadas.
Elevation	0–500 m. (0–1600 ft.)	0–800 m. (0–2600 ft.)
Distribution	AZ; Mexico (Baja California, Baja California Sur, Sinaloa, Sonora)	AZ; Mexico (Baja California, Baja California Sur, Sonora) [WildflowerSearch map] [BONAP county map]
Discussion	In Arizona, Jatropha canescens is found only in Pima County, primarily in Organ Pipe Cactus National Monument. Jatropha canescens is part of a hybrid complex that includes the Mexican species J. cinerea (Ortega) Müller Arg. and, probably, J. giffordiana Dehgan & G. L. Webster. These can be difficult to distinguish. R. McVaugh (1945) suggested considering J. canescens as a synonym of J. cinerea, and F. Shreve and I. L. Wiggins (1964), as well as others, have done so. Jatropha canescens may be distinguished from J. cinerea and J. giffordiana most reliably by its crowded inflorescences of staminate flowers with smaller subglobose (as opposed to urceolate) whitish gray corollas (sometimes with some red or pink on the adaxial surface) as opposed to larger darker red corollas of J. cinerea and J. giffordiana. In addition, J. canescens generally has more numerous, longer and darker colored short shoots, and smaller and less often shallowly 3-lobed leaves. Although J. cinerea (in the strict sense) does not occur in northern Sonora, it is one of the more common plants in Baja California, Baja California Sur, and western mainland Mexico. (Discussion copyrighted by Flora of North America; reprinted with permission.)	In Arizona, Jatropha cuneata is found only in Pima County, primarily in Organ Pipe Cactus National Monument and Cabeza Prieta National Wildlife Refuge. Its stems have been used in basket making. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 12, p. 202.	FNA vol. 12, p. 203.
Parent taxa	Euphorbiaceae > Jatropha	Euphorbiaceae > Jatropha
Sibling taxa	J. cardiophylla, J. cathartica, J. cuneata, J. curcas, J. dioica, J. gossypiifolia, J. integerrima, J. macrorhiza, J. multifida	J. canescens, J. cardiophylla, J. cathartica, J. curcas, J. dioica, J. gossypiifolia, J. integerrima, J. macrorhiza, J. multifida
Synonyms	Mozinna canescens
Name authority	(Bentham) Müller Arg.: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 1079. (1866)	Wiggins & Rollins: Contr. Dudley Herb. 3: 272, plate 62, fig. 1. (1943)
Web links	WildflowerSearch iNaturalist (observations) LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search	WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Jatropha cuneata

Arizona nettlespurge, sangre de drago

leatherplant, limberbush, physicnut, sangre de drago

Habit

Shrubs, to 1.2–2.5 m, dioecious.

Shrubs, to 2 m, dioecious.

Stems

erect, grayish white, branched from base, woody-succulent, canescent; short shoots common;

latex watery, cloudy-whitish.

spreading, yellow to yellow-brown [gray], much-branched, woody-succulent, glabrous; short shoots common;

latex watery, yellow in young shoots, red in older shoots.

Leaves

deciduous, mostly ± evenly distributed on long shoots, few on short shoots;

stipules absent;

petiole 1.3–3 cm, not stipitate-glandular;

blade cordate to broadly ovate, 2.2–3.5 × 1.6–3 cm, unlobed or shallowly 3-lobed, base truncate-cordate, margins entire, apex rounded, ± coriaceous, abaxial surface canescent, adaxial surface sparingly hairy;

venation pinnate (palmate if lobed).

deciduous, usually fascicled on short shoots;

stipules absent;

petiole 0(–0.2) cm, not stipitate-glandular;

blade obovate-spatulate, 0.7–1.9 × 0.3–0.9 cm, unlobed (shallowly 3-lobed on active shoots), base attenuate, margins entire, apex usually rounded, sometimes emarginate, coriaceous, surfaces glabrous;

venation pinnate (palmate if lobed).

Inflorescences

terminal on branches or on short shoots, staminate cymes, pistillate fascicles, or flowers solitary;

peduncle 1–2.6 cm;

bracts 1–2.5 mm, margins entire, sparsely hairy.

on short shoots, cymes or flowers solitary;

peduncle 0.4–0.6 cm;

bracts 0.4–1 mm, margins entire, glabrous.

Pedicels

2–3 mm.

1–4(–6.5) mm.

Staminate flowers

sepals connate to 1/4 length, lanceolate, 2–2.5 × 0.5–0.8 mm, margins entire, apex acute, canescent abaxially, glabrous or sparingly hairy adaxially;

corolla grayish white, sometimes pinkish abaxially, subglobose-urceolate, petals connate 3/4–4/5 length, 5–8 × 1–2 mm, surfaces sparingly hairy;

stamens 10 in 2 whorls (5 + 5);

filaments of outer whorl connate 1/2 length, of inner whorl connate 1/4 length, outer whorl 2–3 mm, whorl series 4–5 mm.

sepals connate basally, ovate-lanceolate, 2.5–4 × 0.6–1 mm, margins entire, apex acute, surfaces glabrous;

corolla white, tubular-urceolate, petals connate most of length, 4–6 × 1.3–2 mm, surfaces glabrous;

stamens 10 in 2 whorls (5 + 5);

filaments of both whorls connate almost to top, outer whorl 1–2.5 mm, inner series 2.5–4 mm.

Pistillate flowers

resembling staminate, but sepals connate only at base, 3–3.5 × 1.5–2 mm;

petals connate 1/2–3/4 length, 8–11 × 3–5 mm;

carpels 2[–3];

styles connate 3/4 their lengths, 2–5 mm.

resembling staminate, but sepals distinct, 1.5–3 × 0.5–1 mm;

petals 4–4.5 × 1–1.5 mm;

carpel 1;

styles 0.5–1 mm.

Capsules

compressed ellipsoidal, 1.2–1.5 × 2–2.5 cm, 2-lobed [ellipsoidal, 3-lobed], tardily dehiscent.

spheric, 0.9–1.1 × 0.9–1.1 cm, tardily dehiscent.

Seeds

solid brown, subspheric, 9–12 mm;

caruncle absent.

solid dark to golden brown, spheric, 10 × 10 mm;

caruncle absent.

= 22 (Mexico).

= 44 (Mexico).

Jatropha canescens

Jatropha cuneata

Phenology

Flowering and fruiting late spring(–summer).

Flowering and fruiting late spring–summer.

Habitat

Sandy washes, sand dunes.

Dry rocky limestone mesas, sandy areas, bajadas.

Elevation

0–500 m. (0–1600 ft.)

0–800 m. (0–2600 ft.)

Distribution

AZ; Mexico (Baja California, Baja California Sur, Sinaloa, Sonora)

AZ; Mexico (Baja California, Baja California Sur, Sonora)

[WildflowerSearch map]

[BONAP county map]

Discussion

In Arizona, Jatropha canescens is found only in Pima County, primarily in Organ Pipe Cactus National Monument.

Jatropha canescens is part of a hybrid complex that includes the Mexican species J. cinerea (Ortega) Müller Arg. and, probably, J. giffordiana Dehgan & G. L. Webster. These can be difficult to distinguish. R. McVaugh (1945) suggested considering J. canescens as a synonym of J. cinerea, and F. Shreve and I. L. Wiggins (1964), as well as others, have done so. Jatropha canescens may be distinguished from J. cinerea and J. giffordiana most reliably by its crowded inflorescences of staminate flowers with smaller subglobose (as opposed to urceolate) whitish gray corollas (sometimes with some red or pink on the adaxial surface) as opposed to larger darker red corollas of J. cinerea and J. giffordiana. In addition, J. canescens generally has more numerous, longer and darker colored short shoots, and smaller and less often shallowly 3-lobed leaves. Although J. cinerea (in the strict sense) does not occur in northern Sonora, it is one of the more common plants in Baja California, Baja California Sur, and western mainland Mexico.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

In Arizona, Jatropha cuneata is found only in Pima County, primarily in Organ Pipe Cactus National Monument and Cabeza Prieta National Wildlife Refuge. Its stems have been used in basket making.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source

FNA vol. 12, p. 202.

FNA vol. 12, p. 203.

Parent taxa

Euphorbiaceae > Jatropha

Sibling taxa

J. cardiophylla, J. cathartica, J. cuneata, J. curcas, J. dioica, J. gossypiifolia, J. integerrima, J. macrorhiza, J. multifida

J. canescens, J. cardiophylla, J. cathartica, J. curcas, J. dioica, J. gossypiifolia, J. integerrima, J. macrorhiza, J. multifida

Synonyms

Mozinna canescens

Name authority

(Bentham) Müller Arg.: in A. P. de Candolle and A. L. P. P. de Candolle, Prodr. 15(2): 1079. (1866)

Wiggins & Rollins: Contr. Dudley Herb. 3: 272, plate 62, fig. 1. (1943)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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Jatropha canescens

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