Asclepias viridula - Florida Natural Areas Inventory

SOUTHERN MILKWEED<br />

<strong>Asclepias</strong> <strong>viridula</strong> Chapm.<br />

Synonyms: none<br />

Family: Asclepiadaceae (milkweed)<br />

FNAI Ranks: G2/S2<br />

Legal Status: US–none FL–Threatened<br />

Wetland Status: US–FACW- FL–FACW<br />

FNAI<br />

Field Description: Perennial herb from a thickened rootstock. Stems erect,<br />

slender, purplish at base, smooth except for a line of small hairs between leaf<br />

nodes. Leaves 2 - 4 inches long, smooth, opposite, very narrow, slightly<br />

widened near tip, 10 - 20 pairs per stem. Flowers 6 - 10, in flat-topped clusters<br />

on stalks in the angle between upper leaves and stem; pale green with<br />

maroon tint; petals curved sharply downward; corona consists of incurving<br />

horns and erect, unlobed hoods that cover the stigma. Fruit an elongated<br />

pod, erect, smooth, up to 4 inches long. All parts of the plant with milky sap.<br />

Similar Species: Carolina milkweed (<strong>Asclepias</strong> cinerea) lacks the line of<br />

stem hairs; it has lavender flowers with lobed hoods shorter than and not<br />

covering the stigma. Michaux’s milkweed (<strong>Asclepias</strong> michauxii) has hairy<br />

stems; pale green flowers in a cluster on main or side branches with hoods<br />

covering the stigma but no horns; leaves are alternate or subopposite.<br />

Related Rare Species: Curtiss’ milkweed (<strong>Asclepias</strong> curtissii), stateendangered,<br />

is found in scrub and sandhill in central peninsular FL.<br />

_______________________________<br />

<strong>Florida</strong> <strong>Natural</strong> <strong>Areas</strong> <strong>Inventory</strong>, 2000

---

Southern milkweed<br />

<strong>Asclepias</strong> <strong>viridula</strong><br />

Habitat: Wet flatwoods and prairies, seepage slopes, pitcherplant bogs.<br />

Best Survey Season: Flowers April–July following fire, otherwise very<br />

difficult to see.<br />

Range-wide Distribution: Endemic to FL Panhandle and NE FL.<br />

Conservation Status: Southern milkweed was once more widespread in<br />

northern FL, but is now mainly found in the Apalachicola National Forest,<br />

where about 30 populations are protected.<br />

Protection & Management: Avoid disruptions to<br />

soil and hydrology, such as bedding, chopping, and<br />

pine planting. Burn every 2 - 3 years.<br />

References: Clewell 1985, Coile 1999, Coile 2000,<br />

Godfrey and Wooten 1981, Wunderlin 1998,<br />

Wunderlin and Hansen 2000a.<br />

hood<br />

horn<br />

flowers in bud<br />

petals<br />

pod<br />

line of hairs<br />

on stem<br />

_______________________________<br />

<strong>Florida</strong> <strong>Natural</strong> <strong>Areas</strong> <strong>Inventory</strong>, 2000