Asclepias curtissii
Asclepias curtissii
Asclepias curtissii (English Curtiss ' milkweed ) is a plant of the genus milkweed ( Asclepias ) from the subfamily of milkweed plants ( Asclepiadoideae ). The area of the species is limited to South Florida. It is very rare and the deposits are highly fragmented. It grows also exclusively on well-drained sandy soils. The specific epithet honors Allen Hiram Curtiss, an American botanist who explored the flora in Florida.
- 5.1 Literature
- 5.2 Notes and references
Features
Vegetative characteristics
Asclepias curtissii is a perennial plant with a fleshy, whitish taproot. The herbaceous shoots die each year from after one growing season and drive in the following year from the taproot new. Per rootstock or taproot only one engine is formed in most cases. Occasionally, even a year is not formed impulse, and the plant drives until the following year again. The first erect, later lying down or leaning against other parts of plants are relatively slim, simple and branched sparse. The branches usually result from injury to the Endsprosses. They are 30 to 70 cm (up to 120 cm: 4 feet ) long and are inconspicuous hairy fluffy or even bald. The latex is white, sticky and viscous. There shall be an average of 14 nodes, the internodes are on average 2.4 cm long. The deep green, mostly opposite, very rarely alternate leaves are stalked, the stalks 4-7 mm long. On average, 22 leaves per plant are formed; the maximum to 55 sheets. Leaf blades, usually with slightly wavy edges, are broadly elliptical, ovate or nearly square with an obtuse tip. The blade end can also be rounded, with a concavity stachelspitzigen, the base is rounded wide. The spreading are 2 to 5 cm long, 1.5 to 3 cm wide, fixed - skinned and bald.
Inflorescence and flowers
The few ( ≈ 3 ), solitary, stalked inflorescences are many flowered (20-30 petals ) and dome- shaped, and arise laterally at some of the top nodes present. The inflorescence stems are slender, 2.5 to 4 cm long and hairy fine fluffy. The fivefold hermaphrodite flowers are zygomorphic, and have a double perianth. The flower stem is thin and hairy 1 to 1.5 cm long and fine fluffy. The flowers are rather small. All flowers of the inflorescence bloom more or less synchronously. The Anthesis lasts about 5 days. The sepals are narrow - lanceolate and 2.5 to 3 mm long. The corolla is wheel-shaped with almost completely folded back Kronblattzipfeln, these are pale green, greenish white to white and about 6 mm long. The single-row, white or cream-colored corona is nearly sessile (ie sessile ), wide - verkehrtkonisch and measures 0.5 mm in length and 2 mm in width. The hood -shaped tip of the staminal corona are oblong - lanceolate and acuminate. They are 4.5 to 5 mm long, greenish white to pale pink colors. However, the color is constant within a plant. The horn-shaped secondary extension is much shorter than the tip and is about half the length of the inside corners to. He is sharply curved inward at the top. The hood -shaped lobes contain nectar. Nectar bags The stylus head is broad - conical with a flattened top and about 1.5 mm long and 3 mm wide
Fruit and seeds
The usually solitary and erect, very rarely paired follicles are spindle -shaped and 14 cm long. The follicle takes about 60 days to maturity and contains an average of about 50 seeds. The seeds have a shock of white hair.
Similar Species
The species is similar in the inflorescence of a Asclepias tuberosa weißblütigen, but is certainly more closely related Asclepias purpurascens.
Geographical distribution and (syn ) Ecology
Asclepias curtissii Gray is limited to two plant communities without exception: scrub and scrubby flat wood; both occur almost exclusively in Florida. Both plant communities need well-drained, deep, sandy and nutrient-poor soils. The scrub community is made up of Pinus clausa, Quercus geminata. Inopina Quercus, Quercus myrtifolia, Quercus chapmanii and Ceratiola ericoides. The " scrubby flat wood" community consists of Pinus palustris, Pinus elliottii, the xerophytic oak species mentioned above, various lichens ( Cladonia spp. Cladina and spp.) And the grass Aristida sp.
This species needs a sunny site and flowers in their natural habitat from April to August, individual plants to October. The flowers produce lots of nectar and therefore attract butterflies to, including Danaus gilippus and the Monarch Butterfly (Danaus plexippus). The plant is also a food plant for the caterpillars of this butterfly species that eat the leaves. The beads of tiger moth species Neoplynes eudora feed on leaves of Asclepias curtissii. The most commonly observed on the flowers butterflies, however, were representatives of the skipper ( Hesperiidae ). Observed Thorybes Pylades, Polites VIBEX, Atalopedes campestris, Hylephila Phyleus, Erynnis zarucco, Erynnis horatius, Wallengrenia Otho and Panoquina ocola. Often Lycaenidae ( Lycaenidae ) were observed: were identified Hemiargus Ceraunus, Strymon melinus and Fixinia Favonius. The fact that these butterflies are the potential pollinators of flowers, prove the glued pollinia. In one case, a copy of Wallengrenia Otho was observed with 9 glued pollinia, in another case, a copy of Hylephila Phyleus with eight glued pollinia. But other insects were, albeit far less frequently observed on the flowers. Even ants talked numerous on the flowers on to drink nectar.
The plants seem to be very old, as did several other species of the genus Asclepias, eg Asclepias meadii. In a garden a copy survived until the time of observation already 25 years old. The specimen had not produced a drive every year. However, you can not reproduce vegetatively itself.
Taxonomy and systematics
The taxon was first classified in 1883 by Asa Gray. The type specimen was collected in 1879 by Allen Hiram Curtiss in Titusville, on the east coast of Florida. It is now in the U.S. National Herbarium in Washington, DC kept.
A junior synonym is Asclepias aceratoides George Valentine Nash (1895 ). Since the name was already assigned by Asclepias aceratoides MACurtis (1849 ), hit Nash in 1896 the new name Asclepias arenicola Nash nn before. Edward Lee Greene transferred to the genus Asclepias arenicola Nash Oxypteryx; Oxypteryx arenicola ( Nash ) Greene is thus also a synonym of Asclepias curtissii. John Kunkel Small in 1933 transferred to the genus Asclepias curtissii also Oxypteryx, 1954 ordered Robert Everard Woodson the taxon again in the genus Asclepias one. The Plant List accepted as a valid taxon Art
Endangering
The species is very rare in the area, the deposits are highly fragmented not only by the strong destruction of habitats, but also by the habitat requirements of the species. Therefore deemed to be at risk. Maybe their rarity, however, overestimated, as many copies drive only every two years, may have some copies even longer periods of rest.