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blood flower, bloodflower milkweed, hierba de la cucaracha, tropical milkweed, wild ipecacuanha

Asclepias cordifolia

heart-leaf milkweed, purple milkweed

Habit Subshrubs or herbs. Herbs.
Stems

1–several, erect, sparsely to moderately branched, 30–150 cm, minutely pilosulous in a line to glabrate, not glaucous, rhizomes absent.

1–20, ascending to spreading, unbranched, 25–100 cm, glabrous, glaucous, rhizomes absent.

Leaves

persistent or gradually caducous from the base, opposite, petiolate, with 1 or 2 stipular colleters on each side of petiole on a ciliate interpetiolar ridge;

petiole 4–25 mm, puberulent with curved trichomes in a line to glabrate;

blade elliptic or oval to linear, 4–18 × 0.3–4.5 cm, membranous, base cuneate, margins entire, apex acute to acuminate to attenuate, venation eucamptodromous to faintly brochidodromous, surfaces sparsely puberulent with curved trichomes on veins abaxially, sparsely puberulent with curved trichomes on veins to glabrate adaxially, margins ciliate, laminar colleters absent.

opposite, sessile, stipular colleters absent;

blade ovate to lanceolate, 3.5–11 × 1.8–8 cm, chartaceous, base cordate, clasping, margins entire, apex acute, mucronate, venation brochidodromous to eucamptodromous, surfaces glabrous, glaucous, margins minutely ciliate, laminar colleters absent.

Inflorescences

extra-axillary, pedunculate, 5–22-flowered;

peduncle 0.5–8 cm, puberulent with curved trichomes in a line, with 1 caducous bract at the base of each pedicel.

terminal, branched, sometimes also extra-axillary at upper nodes, pedunculate, 5–20-flowered;

peduncle 0.3–6.5 cm, apically sparsely pilose to glabrate, with few bracts.

Pedicels

7–20 mm, puberulent with curved trichomes.

16–37 mm, sparsely pilose.

Flowers

erect;

calyx lobes linear-lanceolate, 3–4 mm, apex acute, puberulent with curved trichomes;

corolla red, sometimes yellow in throat (to wholly orange or yellow in cultivars), lobes reflexed with spreading tips, elliptic to oval, 6–9 mm, apex acute, glabrous abaxially, minutely papillose at base adaxially;

gynostegial column 2–2.5 mm;

fused anthers yellowish green to tan, cylindric, 1.5–2 mm, wings narrowly right-triangular, closed, apical appendages deltoid;

corona segments yellow to orange, stipitate, tubular, dorsally somewhat flattened, 3.5–4 mm, exceeding style apex, apex obtuse to acute, glabrous, internal appendage falcate, exserted, arching over style apex, glabrous;

style apex shallowly depressed, yellow.

erect to pendent;

calyx lobes elliptic to lanceolate, 3–5 mm, apex acute, pilose;

corolla red-violet, lobes reflexed with spreading tips, oval, 6–7 mm, apex acute, glabrous;

gynostegial column 1–1.5 mm;

fused anthers brown, cylindric, 1.5–2 mm, wings right-triangular, open at tip, apical appendages deltoid;

corona segments white, tinged pink to red-violet at base, sessile, tubular, 2–3 mm, exceeded by style apex, base saccate, apex truncate, oblique, glabrous, internal appendage absent;

style apex shallowly depressed, pink to red-violet.

Seeds

ovate, 6–7 × 4–5 mm, margin winged, faces minutely rugulose to smooth;

coma 2.5–3 cm.

ovate, 8–9 × 5–7 mm, margin not winged, faces reticulate-rugulose;

coma 3–3.5 cm.

Follicles

erect on straight pedicels, fusiform, 6–10 × 0.5–1.2 cm, apex acuminate to attenuate, smooth, glabrous.

erect on upcurved pedicels, lance-ovoid, 7.5–10.5 × 1.5–1.8 cm, apex long-acuminate, smooth, glabrous, glaucous.

2n

= 22.

= 22.

Asclepias curassavica

Asclepias cordifolia

Phenology Flowering and fruiting year-round. Flowering Mar–Jul(–Aug); fruiting Jun–Sep.
Habitat Disturbed areas, fields, orchards, and gardens, canal banks, ditches, streamsides, wet prairies, marshes, swamps, coastal dunes, sandy soils. Hill­sides, canyons, ridge tops, streamsides, seeps, basalt, serpentine, gabbro, granite, shale, limestone, talus slopes, gravel, alluvium, oak woodlands, mixed ever­green, douglas-fir, pine, pine-oak, and riparian forests, chaparral, timberline meadows, grasslands.
Elevation 0–100 m. [0–300 ft.] 50–2200(–2800) m. [160–7200(–9200) ft.]
Distribution
from FNA
CA; FL; LA; TX; Mexico; Central America; South America; West Indies [Introduced in North America; introduced also to Old World tropics]
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
Discussion

Asclepias curassavica is the only non-native Asclepias species naturalized in the flora area. It is very commonly cultivated, originally for its strikingly colored flowers and their attraction of Lepidoptera and Hymenoptera. Recently, they have been valued also as a host plant for monarch butterflies. Cultivars with pure orange or pure yellow flowers are readily available. The species develops rapidly from seed and can be grown as an annual (in the horticultural sense) anywhere in the region. Though often described as an annual, like all species of Asclepias, it has a perennial habit. It may persist through mild winters at least as far north as Oklahoma but has only become established in frost-free areas of the southern United States.

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

Fresh leaves and stems of Asclepias cordifolia are often slightly or strongly colored bluish, grayish, or purplish. This is one of the few American species of Asclepias with cavitate corona segments that lack adaxial appendages. Such species were segregated along with diverse African species in Gomphocarpus R. Brown, a polyphyletic segregate (M. Fishbein et al. 2011; D. Chuba et al. 2017). Asclepias cordifolia is a distinctive species unlike any other within its range. It is phylogenetically and geographically isolated, although not highly derived morphologically. In Nevada, A. cordifolia is restricted to the Sierra Nevada, in Carson City, Douglas, and Washoe counties. Its range extends to northern California and southwestern Oregon.

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

Parent taxa Apocynaceae > Asclepias Apocynaceae > Asclepias
Sibling taxa
A. albicans, A. amplexicaulis, A. angustifolia, A. arenaria, A. asperula, A. brachystephana, A. californica, A. cinerea, A. connivens, A. cordifolia, A. cryptoceras, A. curtissii, A. cutleri, A. eastwoodiana, A. elata, A. emoryi, A. engelmanniana, A. eriocarpa, A. erosa, A. exaltata, A. fascicularis, A. feayi, A. hallii, A. hirtella, A. humistrata, A. hypoleuca, A. incarnata, A. involucrata, A. labriformis, A. lanceolata, A. lanuginosa, A. latifolia, A. lemmonii, A. linaria, A. linearis, A. longifolia, A. macrosperma, A. macrotis, A. meadii, A. michauxii, A. nummularia, A. nyctaginifolia, A. obovata, A. oenotheroides, A. ovalifolia, A. pedicellata, A. perennis, A. prostrata, A. pumila, A. purpurascens, A. quadrifolia, A. quinquedentata, A. rubra, A. rusbyi, A. ruthiae, A. sanjuanensis, A. scaposa, A. solanoana, A. speciosa, A. sperryi, A. stenophylla, A. subulata, A. subverticillata, A. sullivantii, A. syriaca, A. texana, A. tomentosa, A. tuberosa, A. uncialis, A. variegata, A. verticillata, A. vestita, A. viridiflora, A. viridis, A. viridula, A. welshii
A. albicans, A. amplexicaulis, A. angustifolia, A. arenaria, A. asperula, A. brachystephana, A. californica, A. cinerea, A. connivens, A. cryptoceras, A. curassavica, A. curtissii, A. cutleri, A. eastwoodiana, A. elata, A. emoryi, A. engelmanniana, A. eriocarpa, A. erosa, A. exaltata, A. fascicularis, A. feayi, A. hallii, A. hirtella, A. humistrata, A. hypoleuca, A. incarnata, A. involucrata, A. labriformis, A. lanceolata, A. lanuginosa, A. latifolia, A. lemmonii, A. linaria, A. linearis, A. longifolia, A. macrosperma, A. macrotis, A. meadii, A. michauxii, A. nummularia, A. nyctaginifolia, A. obovata, A. oenotheroides, A. ovalifolia, A. pedicellata, A. perennis, A. prostrata, A. pumila, A. purpurascens, A. quadrifolia, A. quinquedentata, A. rubra, A. rusbyi, A. ruthiae, A. sanjuanensis, A. scaposa, A. solanoana, A. speciosa, A. sperryi, A. stenophylla, A. subulata, A. subverticillata, A. sullivantii, A. syriaca, A. texana, A. tomentosa, A. tuberosa, A. uncialis, A. variegata, A. verticillata, A. vestita, A. viridiflora, A. viridis, A. viridula, A. welshii
Synonyms Acerates cordifolia, Gomphocarpus cordifolius
Name authority Linnaeus: Sp. Pl. 1: 215. (1753) (Bentham) Jepson: Fl. W. Calif., 384. (1901)
Source FNA vol. 14. Treatment author: Mark Fishbein. FNA vol. 14. Treatment author: Mark Fishbein.
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