Asclepias

Contains 22 accepted taxa overall.

Characteristics
Asclepias L.
APOCYNACEAE
MILKWEED
View USF Herbarium specimens of this family
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Classification
GENTIANALES
Asclepias
Citation
ASCLEPIAS Linnaeus, Sp. Pl. 214. 1753.
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TYPE: Asclepias syriaca Linnaeus Lectotypified by Britton & A. Brown, Ill. Fl. N. U.S., ed. 2. 3: 24. 1913.
Species
Scientific Name Common Name Herbarium Specimens Status Photos
Asclepias amplexicaulis CLASPING MILKWEED Native
Asclepias cinerea CAROLINA MILKWEED Native FAC (NWPL)
Asclepias connivens LARGEFLOWER MILKWEED Native OBL (NWPL) FACW (DEP)
Asclepias curassavica SCARLET MILKWEED; BLOODFLOWER Not Native FAC (NWPL)
Asclepias curtissii CURTISS' MILKWEED Native Endemic Endangered-State
Asclepias feayi FLORIDA MILKWEED Native Endemic
Asclepias humistrata PINEWOODS MILKWEED Native
Asclepias incarnata SWAMP MILKWEED Native OBL (NWPL) OBL (DEP)
Asclepias lanceolata FEWFLOWER MILKWEED Native OBL (NWPL) OBL (DEP)
Asclepias longifolia LONGLEAF MILKWEED Native FAC (NWPL) FACW (DEP)
Asclepias michauxii MICHAUX'S MILKWEED Native FAC (NWPL)
Asclepias obovata PINELAND MILKWEED Native
Asclepias pedicellata SAVANNAH MILKWEED Native FACW (NWPL) FACW (DEP)
Asclepias perennis SWAMP MILKWEED Native OBL (NWPL) OBL (DEP)
Asclepias rubra RED MILKWEED Native OBL (NWPL) OBL (DEP)
Asclepias tomentosa VELVETLEAF MILKWEED Native
Asclepias tuberosa BUTTERFLYWEED; BUTTERFLY MILKWEED Native
Asclepias variegata REDRING MILKWEED Native FACU (NWPL)
Asclepias verticillata WHORLED MILKWEED Native FACU (NWPL)
Asclepias viridiflora GREEN MILKWEED Native Endangered-State
Asclepias viridis GREEN ANTELOPEHORN Native
Asclepias viridula SOUTHERN MILKWEED; GREEN MILKWEED Native Threatened-State FACW (NWPL) FACW (DEP)
[Family identification key]
1.  Leaves mostly or all alternate, especially distally, occasionally some subopposite to opposite especially on proximal nodes
Key A
1.  Leaves opposite, subopposite, or whorled
Key B
1.  (Key A) Sap clear; corolla reddish orange to orange, rarely yellow in Florida
2
1.  Sap white; corolla white, pink, purple, to greenish
4
2.  Leaf blade base usually hastate with cripsate-revolute margins
A. tuberosa subsp. rolfsii
2.  Leaf blade base cuneate, obtuse, rounded, truncate, to subcordate, the margins plane
3
3.  Leaf blade base truncate or obtuse to cordate, the apex acute to attenuate
A. tuberosa subsp. interior
3.  Leaf blade base cuneat to subcordate, the apex rounded to acute
A. tuberosa subsp. tuberosa
4.  Leaf blades ovate to lance-oblong
A. viridis
4.  Leaf blades linear to linear-lanceolate
5
5.  Basal branches often ascending to erect; leaves not secund; stems with 1-many inflorescence nodes of 1-3 umbels; corona segments compressed and laminar, appendages absent; fruiting pedicel upcurved
A. longifolia
5.  Basal branches often spreading; leaves sometimes secund; stems with 1 inflorescence node of 1-3 umbels; corona segments cupulate, the appendages exserted; fruiting pedicel straight and erect
A. michauxii
1.  (Key B; corona segments or hoods, corona appendage or horn) Corolla lobes erect at anthesis
2
1.  Corolla lobes reflexed at anthesis
3
2.  Leaves 2-6 mm wide; corolla greenish yellow
A. pedicellata
2.  Leaves 15-30 mm wide; corolla greenish white
A. viridis
3.  Corolla lobes yellow, orange, orange-red, to scarlet
4
3.  Corolla lobes white, pink, purple, to greenish
5
4.  Leaves 16-70 times longer than wide, usually <1 cm wide
A. lanceolata
4.  Leaves 4-10 times longer than wide, usually >1 cm wide, at least larger ones
A. curassavica
5.  Leaves oblong to ovate
6
5.  Leaves linear to lanceolate
13
6.  Leaves sessile or subsessile; umbels pedunculate, the peduncle subequal to longer than the pedicels
7
6.  Leaves petiolate, or if subsessile, the umbels sessile
9
7.  Leaves broadly cuneate at base; corolla greenish yellow
A. connivens
7.  Leaves auriculate-clasping at base; corolla purple or purplish green
8
8.  Leaves elliptic; corolla lobes 9-11 mm long
A. amplexicaulis
8.  Leaves ovate-deltoid; corolla lobes 5-6 mm long
A. humistrata
. 
A. cinerea
9.  Umbel peduncle subequal to longer than the pedicels
10
9.  Umbel peduncle shorter than the pedicels
11
10.  Larger leaves usually <4 cm long; inflorescence lateral; corona hood narrowly lanceolate
A. curtissii
10.  Larger leaves usually >5 cm long; inflorescence terminal; corona hood broadly rounded
A. variegata
11.  Corolla lobes 6-7 mm long, corona appendage absent or obscure
A. viridiflora
11.  Corolla lobes 9-10 mm long, corona appendage present
12
12.  Longest petioles usually <4 mm long; corona segments longer than the appendage
A. obovata
12.  Longest petioles usually >4 mm long; corona segments shorter than the appendage
A. tomentosa
13.  Leaves whorled
A. verticillata
13.  Leaves opposite to subopposite
14
14.  Corona segments shorter than the gynostegium
15
14.  Corona segments longer than the gynostegium
17
15.  Corona appendage present
A. cinerea
15.  Corona appendage absent
16
16.  Larger leaves <1.5 mm wide; corolla lobes spreading, 6-8 mm long
A. feayi
16.  Larger leaves >1.5 mm wide; corolla lobes reflexed, 2-5 mm long
A. longifolia
17.  Inflorescence umbels terminal
A. michauxii
17.  Inflorescence umbels terminal and from the upper leaf axils
18
18.  Leaves 1-2 mm wide
A. viridula
18.  Leaves 5-10 mm wide
19
19.  Leaves sessile or subsessile
A. rubra
19.  Leaves petiolate
20
20.  Leaf blade base rounded to short-tapering; corolla dull rose-purple
A. incarnata
20.  Leaf blade base long tapering; corolla white to pale pink
A. perennis
Genus Synonyms
Synonym Full Citation Basionym Type
Acerates Acerates Elliott, Sketch Bot. S. Carolina 1: 316. 11817. TYPE: Acerates longifolia (Michaux) Elliott (Asclepias longifolia Michaux)
Anantherix Anantherix Nuttall, Gen. N. Amer. Pl. 1: 169. 1818. TYPE: Anantherix viridis (Walter) Nuttall (Asclepias viridis Walter)
Anthanotis Anthanotis Rafinesque, Fl. Ludov. 52, 149. 1817. TYPE: Anthanotis procumbens Rafinesque
Asclepiodella Asclepiodella Small, Man. S.E. Fl. 1073, 1507. 1933. TYPE: Asclepiodella feayi (Chapman) Small (Asclepias feayi Chapman)
Asclepiodora Asclepiodora A. Gray, Proc. Amer. Acad. Arts 12: 66. 1876. TYPE: Ascleipiodora viridis (Walter) A. Gray (Asaclepias viridis Walter) Lectotypified by Woodson, Ann. Missouri Bot. Gard. 41: 47. 1954. = Anantherix Nuttall 1818, by lectotypification.
Biventraria Biventraria Small, Man. S.E. Fl. 1072, 1507. 1933. TYPE: Biventraria variegata (Linnaeus) Small (Asclepias variegata Linnaeus)
Oligoron Oligoron Rafinesque, New Fl. 4: 60. 1838 ("1836"). TYPE: = Acerates Elliott 1817.
Otanema Otanema Rafinesque, New Fl. 4: 61. 1838 ("1836"). TYPE: Otanema latifolia Rafinesque Lectotypified by Woodson, Ann. Missouri Bot. Gard. 41: 47. 1954.
Otaria Otaria Kunth, in Humboldt et al., Nov. Gen. Sp. 3: 192, t. 228. 1819. TYPE: Otaria auriculata (Kunth) G. Don (Asclepias auriculata Kunth)
Oxypteryx Oxtpteryx Greene, Pittonia 3: 234. 1897. TYPE: Oxypteryx arenicola (Nash) Greene (Asclepias arenicola Nash; Asclepias aceratoides Nash 1895, non M. A. Curtis 1849.
Podostemma Podostemma Greene, Pittonia 3: 235. 1897. TYPE: Podostemma longicornu (Bentham) Greene (Asclepias longicornu Bentham)
Podostigma Podostigma Elliott, Sketch Bot. S. Carolina 1: 326. 1817. TYPE: Podostigma pubescens Elliott, nom. illegit. Asclepias pedicellata Walter; Podostigma pedicellata (Walter) Vail)
Polyotus Polyotus Nuttall, Trans. Amer. Philos. Soc., ser. 2. 5: 199. 1837. TYPE: = Acerates Elliott 1817.
Schizonotus Schizonotus A. Gray, Proc. Amer. Acad. Arts 12: 66. 1877, non Lindley 1830 (nom. rej.), nec Rafinesque 1838 (nom. rej.). TYPE: Schizonotus purpurascens A. Gray = Solanoa Greene 1890.
Solanoa Solanoa Greene, Pittonia 2: 67. 1890. TYPE: Solanoa purpurascens (A. Gray) Greene (Schizonotus purpurascens A. Gray) Substitute name for Schizonotus A. Gray 1877, non Lindley 1830, nec Rafinesque 1838.
Stylandra Stylandra Nuttall, Gen. N. Amer. Pl. 1: 170. 1818. TYPE: Stylandra pumila Nuttall, nom. illegit. (Asclepias pedicellata Walter) = Podostigma Elliott 1817.