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Asclepias cordifolia

heart-leaf milkweed, purple milkweed

Feay's milkweed, Florida milkweed

Habit Herbs. Herbs.
Stems

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

solitary, erect, unbranched (rarely near base), 20–75 cm, minutely puberulent in a line with curved trichomes to glabrate, not glaucous, rhizomes absent.

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, sessile, with 1 or 2 stipular colleters on each side of leaf base;

blade filiform, 2.5–10 × 0.1–0.15 cm, membranous, base cuneate, margins entire, apex acute, venation obscure, surfaces glabrous, laminar colleters absent.

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 often extra-axillary at upper nodes, sessile or pedunculate, 2–7-flowered;

peduncle 0–5 cm, puberulent with curved trichomes on 1 side, with 1 caducous bract at the base of each pedicel.

Pedicels

16–37 mm, sparsely pilose.

7–17 mm, minutely puberulent with curved trichomes on 1 side.

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;

calyx lobes narrowly lanceolate, 1.5–2.5 mm, apex acute, glabrous;

corolla white, sometimes pale lavender-tinged, inconspicuously striate, lobes spreading, lanceolate, 7–10 mm, apex acute to obtuse, glabrous;

gynostegium sessile;

fused anthers lavender, cylindric, 1.5–3 mm, wings narrowly right-triangular, open at base, apical appendages ovate;

corona segments white, sessile with a basal collar, cupulate, 2.5–4 mm, equaling to slightly exceeding style apex, apex obtuse, glabrous, internal appendage a laterally flattened, included crest, glabrous;

style apex shallowly depressed, lavender.

Seeds

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

coma 3–3.5 cm.

oval, 6–8 × 3–5 mm, margin winged, faces smooth;

coma 3.5 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 straight pedicels, fusiform, 9–12 × 0.3–0.6 cm, apex attenuate, smooth, glabrous.

2n

= 22.

Asclepias cordifolia

Asclepias feayi

Phenology Flowering Mar–Jul(–Aug); fruiting Jun–Sep. Flowering (Feb–)Apr–Sep(–Nov); fruiting Jun–Aug.
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. Flats, streamsides, sandy soils, pine scrub and flatwoods, pine-palmetto scrub, prairies, hammocks.
Elevation 50–2200(–2800) m. [160–7200(–9200) ft.] 0–50 m. [0–160 ft.]
Distribution
from FNA
CA; NV; OR
[WildflowerSearch map]
[BONAP county map]
from FNA
FL
[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 feayi is one of a trio of very slender milkweeds in the southeastern United States, along with A. cinerea and A. viridula. These species are divergent in floral morphology, but without flowers they are very difficult to distinguish (even in fruit), and they appear to be close relatives. However, A. feayi occurs primarily in peninsular central and southwestern Florida, from Lake to Collier counties, most commonly in scrub. A single disjunct population has been documented from Clay County in the northeastern part of the state (Hall 1896 [FLAS]). Asclepias cinerea and A. viridula are found in northern Florida or further north, in flatwoods. All three species are cryptic in the absence of flowers and appear to respond positively to fire and rainfall events. They are likely to be more common than is apparent because they are inconspicuous and emerge episodically. Nonetheless, numerous historical locations for A. feayi have been developed and are no longer capable of supporting populations, and its conservation status merits evaluation. An unusual putative hybrid with A. pedicellata represented by a single collection is documented from Marion County (Judd 2639 [FLAS]), suggested by the exactly intermediate floral morphology.

(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. eriocarpa, A. erosa, A. exaltata, A. fascicularis, 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 Asclepiodella feayi
Name authority (Bentham) Jepson: Fl. W. Calif., 384. (1901) A. Gray: Proc. Amer. Acad. Arts 12: 72. (1876)
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