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

Florida milkweed, long-leaf milkweed

large-flower milkweed

Habit Herbs. Herbs.
Stems

1–few, spreading to decumbent, unbranched, 25–70 cm, puberulent with curved trichomes, not glaucous, rhizomes absent.

1, erect, unbranched (rarely branched), 25–90 cm, minutely puberulent with curved trichomes or pilose to glabrate, not glaucous, rhizomes absent.

Leaves

opposite or alternate, sessile or petiolate, with 1 or 2 stipular colleters on each side of petiole, also in axil;

petiole 0–2 mm, puberulent with curved trichomes;

blade linear to linear-lanceolate, 5–18 × 0.2–1 cm, chartaceous, base cuneate, margins entire, apex acute to attenuate, sometimes mucronate, venation brochidodromous, surfaces scabridulous to puberulent with curved trichomes, especially on veins, margins ciliate, laminar colleters absent.

opposite, sessile or petiolate, with 1 or 2 stipular colleters on each side of petiole;

petiole 0–1 mm, puberulent with curved trichomes to glabrate;

blade narrowly elliptic to linear or oblanceolate, 2.5–8 × 0.3–2.5 cm, chartaceous, base cuneate, margins entire, apex acute to rounded, mucronate, venation brochidodromous, surfaces sparsely pilose to glabrate, midvein puberulent with curved trichomes to glabrate, margins ciliate, 0–6 laminar colleters.

Inflorescences

terminal and extra-axillary at upper nodes, sessile or pedunculate, 13–28(–36)-flowered;

peduncle 0–6 cm, puberulent with curved trichomes, with 1 caducous bract at the base of each pedicel.

terminal, sometimes branched, and extra-axillary at upper nodes, pedunculate, 4–8-flowered;

peduncle 0.9–6 cm, densely puberulent with curved trichomes, with 1 caducous bract at the base of each pedicel.

Pedicels

9–16 mm, puberulent with curved trichomes.

10–20 mm, densely puberulent with curved trichomes.

Flowers

erect to spreading;

calyx lobes narrowly lanceolate, 1.5–2 mm, apex acute, puberulent with curved trichomes;

corolla white to greenish cream, purple at lobe tips, lobes reflexed, oblong, 3–5 mm, apex obtuse, glabrous;

gynostegial column 0.2–0.5 mm;

fused anthers green or brown, cylindric, 1–1.5 mm, wings triangular to trapezoidal, widest at middle, slightly open at tip, apical appendages ovate;

corona segments pinkish lavender to red-violet, often with white apex, often a darker red-violet stripe or at base, sessile, laminar, strongly dorsally compressed, margins incurved, appressed to column, curved to subsaccate, 2–2.5 mm, exceeding point of anther wings, greatly exceeded by style apex, apex obtuse to truncate, glabrous, internal appendage absent or obscure, glabrous;

style apex shallowly depressed, greenish cream to green.

spreading to pendent;

calyx lobes lanceolate, 4–6 mm, apex acute, sparsely pilosulous;

corollas green, sometimes tinged brown at apex, lobes reflexed with spreading tips, elliptic, 10–13 mm, apex acute to obtuse, sometimes emarginate, glabrous;

gynostegial column 1–1.5 mm;

fused anthers green, obconic, 3–3.5 mm, wings narrowly right-triangular, distended at base, closed, apical appendages oval;

corona segments cream to pale green, stipitate, clavate, incurved, 8–10 mm, greatly exceeding style apex, apex rounded, glabrous, internal appendage a hidden crest, glabrous, apices of the 5 segments sometimes connivent;

style apex depressed, green.

Seeds

ovate, 11–12 × 7–8 mm, margin winged, faces smooth;

coma 4–5 cm.

ovate, 7–9 × 5–6 mm, margin winged, faces minutely and sparsely rugulose;

coma 3–3.5 cm.

Follicles

erect on upcurved pedicels, narrowly fusiform, 8–13.5 × 0.7–1.2 cm, apex attenuate, smooth, puberulent with curved trichomes.

erect on upcurved pedicels, fusiform, 11.5–15 × 0.5–1.4 cm, apex long-attenuate, smooth, minutely pilosulous.

Asclepias longifolia

Asclepias connivens

Phenology Flowering (Jan–)Feb–Sep(–Oct); fruiting Apr–Aug. Flowering May–Aug(–Sep); fruiting Jul–Sep(–Nov).
Habitat Bogs, swamps, flats, ditches, depressions, pond edges, sandy, clay, and rocky soils, wet prairies, pine flatwoods, oak woodlands, savannas, pastures, often following fires. Flats, sandy soils, pine flatwoods and barrens, often recently burned, wet meadows, marshes, bogs, swamps.
Elevation 0–100 m. (0–300 ft.) 0–200 m. (0–700 ft.)
Distribution
from FNA
AL; DE; FL; GA; LA; MS; NC; SC; VA
[WildflowerSearch map]
[BONAP county map]
from FNA
AL; FL; GA; SC
[WildflowerSearch map]
[BONAP county map]
Discussion

Asclepias longifolia has sometimes been treated to include A. hirtella as conspecific, as discussed under that species. As circumscribed here, the distribution of A. longifolia extends along the Atlantic Coastal Plain south of Delaware to Florida and westward to the Mississppi River. Reports of A. longifolia from west of the Mississippi River in Louisiana and in Texas are assigned here to A. hirtella. Hence, the range of A. longifolia in Louisiana is extremely limited, and the conservation status of this species warrants assessment in that state (Livingston, Saint Helena, Saint Tammany, Tangipahoa, and Washington parishes). Reports of A. longifolia from Maryland and West Virginia have not been confirmed, and the species is considered extirpated from Delaware. Otherwise, it is rare at the northern extent of its range and considered to be of conservation concern in North Carolina and Virginia (Greensville and Prince George counties).

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

Asclepias connivens is a singular species—the large, incurved, clavate corona segments are unlike any others in the genus. With wide leaves and large flowers, A. connivens is more conspicuous than most co-occurring milkweeds, such as A. cinerea, A. feayi, A. pedicellata, and A. viridula. It prefers wet soils and often occurs at the same sites as A. viridula and the red-orange-flowered A. lanceolata. Asclepias connivens barely enters South Carolina in Jasper and Beaufort counties and is considered rare and to be of conservation concern in that state. It has been reported from Mississippi, but there are no specimens from that state, and occurrence there seems unlikely, as A. connivens has not been documented from southwestern Alabama either. It would be interesting to discover what pollinates the large and unusual flower of A. connivens; however, there appear to be no reports of flower visitors to this species.

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

Source FNA vol. 14. FNA vol. 14.
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. 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. 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. 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. 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 floridana, A. longifolia, A. floridana Anantherix connivens
Name authority Michaux: Fl. Bor.-Amer. 1: 116. (1803) Baldwin in Elliott: Sketch Bot. S. Carolina 1: 320. (1817)
Web links