The green links below add additional plants to the comparison table. Blue links lead to other Web sites.
enable glossary links
Asclepias cordifolia

heart-leaf milkweed, purple milkweed

Indian milkweed, kotolo, woollypod milkweed, wooly-pod or kotolo or Indian milkweed

Habit Herbs. Herbs.
Stems

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

1–10, erect to spreading, rarely branched, 30–100 cm, tomentose to puberulent with curved trichomes or glabrate, not glaucous, rhizomatous.

Leaves

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.

opposite, or alternate or whorled at upper nodes, petiolate, with 0–2 stipular colleters on each side of petiole (sometimes additionally in the axil);

petiole 4–15 mm, tomentose;

blade oblong or oval to lanceolate or ovate, often conduplicate, 8–20 × 2–8 cm, chartaceous, base obtuse or truncate to cordate, margins entire or often undulate, apex acuminate to obtuse, mucronate, venation brochidodromous, surfaces tomentose to densely puberulent with curved trichomes, margins ciliate, 6–8 laminar colleters.

Inflorescences

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.

terminal, sometimes branched, and extra-axillary at upper nodes, pedunculate, 12–57-flowered;

peduncle 1–10 cm, densely tomentose, with 1 caducous bract at the base of each pedicel.

Pedicels

16–37 mm, sparsely pilose.

15–50 mm, densely tomentose.

Flowers

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.

erect to spreading;

calyx lobes lanceolate, 3–4 mm, apex acute, densely tomentose;

corolla greenish cream, ochroleucous, or pinkish cream, deep pink or tan abaxially, lobes reflexed, tips usually spreading, oval, 7–9 mm, apex acute, tomentose abaxially towards tips, glabrous adaxially;

gynostegial column 1–1.5 mm;

fused anthers dark brown, cylindric, 2.5–3 mm, wings right-triangular, closed, apical appendages ovate;

corona segments cream to dark pink, stipitate, conduplicate, dorsally rounded, 2.5–3 mm, exceeded by style apex, apex truncate, oblique, papillose, internal appendage falcate, exserted, sharply inflexed towards style apex, papillose;

style apex shallowly depressed, cream.

Seeds

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

coma 3–3.5 cm.

ovate, 7–9 × 4–6 mm, margin narrowly winged, faces faintly rugulose;

coma 2.5–3 cm.

Follicles

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

erect on upcurved pedicels, lance-ovoid, 5–10 × 1.5–3 cm, apex apiculate, smooth, densely tomentose.

2n

= 22.

Asclepias cordifolia

Asclepias eriocarpa

Phenology Flowering Mar–Jul(–Aug); fruiting Jun–Sep. Flowering (Apr–)May–Oct; fruiting (May–)Jun–Oct.
Habitat 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. Hills, slopes, ridge tops, flats, valleys, canyons, arroyos, stream banks, granite, rocky, alluvial, clay, and sandy soils, meadows, native and non-native grasslands, cha­parral, coastal sage scrub, oak and pine-oak wood­lands, pine, mixed conifer, and riparian forests, often following fires.
Elevation 50–2200(–2800) m. [160–7200(–9200) ft.] 50–2500 m. [160–8200 ft.]
Distribution
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
CA; Mexico (Baja California)
[WildflowerSearch map]
[BONAP county map]
Discussion

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.)

Asclepias eriocarpa is found almost throughout the California Floristic Province in relatively dry, open sites in a variety of vegetation types. It is the only milkweed in the flora area that regularly produces alternate, opposite, and whorled leaves on a single stem. Its distribution overlaps that of several other broad-leaved, densely vestitured Asclepias species: A. erosa in desert scrub and dry grasslands, A. californica and A. vestita in chaparral and woodlands, and A. speciosa in woodlands. Comparison to A. erosa is presented under that species. Asclepias eriocarpa is easily distinguished from A. californica by the distinctive red-violet, rounded corona segments that lack appendages in the latter species. Asclepias eriocarpa has corona segments with truncate apices and corolla lobes that are tomentose abaxially only at the apex, in contrast to the obtuse corona segments and uniformly pubescent corolla lobes of A. vestita. Asclepias speciosa has distinctive corona segments with long, tapering apices that are much larger than and are easily distinguished from those of A. eriocarpa. It is possible that A. eriocarpa and A. speciosa occasionally hybridize—R. E. Woodson Jr. speculated (via annotation of the holotype, E. Gifford s.n. [CAS]) that A. giffordii Eastwood represented such a hybrid. That interpretation is accepted here. Asclepias eriocarpa is reported to be a resource for fiber and medicine by Native Americans.

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

Source FNA vol. 14. Treatment author: Mark Fishbein. FNA vol. 14. Treatment author: Mark Fishbein.
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. 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
A. albicans, A. amplexicaulis, A. angustifolia, A. arenaria, A. asperula, A. brachystephana, A. californica, A. cinerea, A. connivens, A. cordifolia, A. cryptoceras, A. curassavica, A. curtissii, A. cutleri, A. eastwoodiana, A. elata, A. emoryi, A. engelmanniana, 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 A. eriocarpa var. microcarpa, A. fremontii, A. kotolo
Name authority (Bentham) Jepson: Fl. W. Calif., 384. (1901) Bentham: Pl. Hartw., 323. (1849)
Web links