Markea

Markea is a genus of flowering plants of the nightshade family (Solanaceae ). The depending on the author 14 or 17 species grow mostly epiphytic.

Description

Vegetative characteristics

Markea are epiphytic plants growing, mostly as lianas, rarer than upright or prostrate shrubs of (rarely only 1) grow 1.5 to 3.5 m height. Only in exceptional cases, it is also up to 6 m tall trees. At the roots often appear thickened. The plants can be myrmekophil. You are busy with a variety of differently shaped hair, this can be simple, branched and branched tree-like, and there is glandular hairs with multicellular heads and a two-celled stalk. The stem axis is (probably in all cases) is hollow and reached a diameter of up to 8 cm.

The leaves seem lively to be in groups of three to six. The leaf blade is usually membranous, rarely leathery and thick, it is narrow or broad elliptic or obovate - elliptic. The base is tapered, pointed, rounded or heart-shaped, often decurrent on stem; the tip is usually pointed, sharpened rare, blunt or rounded. In some species, the average size of leaf blades (2.1 ) 4.5 to 9 (13 ) × 2-5 (6.8 ) cm, in other ways they are larger, ( 7) 10-22 (31 ) have × ( 2.9 ) 4-10 (14 ) cm. The petioles are 6-25 (60 ) mm long.

Inflorescences and flowers

The fragrant, sometimes foul-smelling or odorless flowers are individually, only in exceptional cases, in pairs or in two to zehnblütigen (in exceptional cases up siebzehnblütigen ) zymösem inflorescences. The inflorescence stems are either ( 3) 12 to 30 (50 ) cm long, filiform, flexible and upright or only 0.3 cm to 16 cm long, thick, rigid and woody. The flower stems are either only 1.5 to 7 mm long or longer and then 15 to 25 mm, rarely up to 63 mm long. Only in exceptional cases the flowers are sessile. The sepals are often slightly deformed, so that the calyx tube is very short or almost non-existent. However, sometimes the calyx tube is made ​​stronger, mostly shorter than the sepals, only in exceptional cases the calyx tube is longer. The crown is red, red-orange, yellow- orange, yellow -green, greenish, greenish- white, purple or blackish - purple colored. It is often divided into the characteristic of the subfamily Juanulloideae two sectors, of which the lower, shorter tubular and the upper long funnel. However, some species have also cup-shaped or funnel-shaped crowns. The length of the crown is variable, they usually ranging from 4.5 to 11 cm, in two species, they are also longer and in a kind of (M. sturmii ) is the crown only about 2.45 cm long. The Corolla lobe wider than long and usually bent back.

In some species the stamens on the crown stand out. The dust bags are fixed to the base, about 9.5 to 18 mm long, in some types hardly 6 to 9.5 mm, they are usually associated inclined. The filaments are longer, shorter or the same length as the dust bag, are at the lower end only hairs and fixed from about 5 to 20 or 30 mm from the crown at this base. The pollen with a diameter from 24 to 38 microns medium size, the pollen grain wall ( exine ) is thick or thin, mostly around the equator pollen scaly or wrinkly. Only in the species M. lopezii possess the pollen grains small spines, Ubisch bodies are only known from six species.

The most pear-shaped ovary is bilobed and zweikammerig. The nectaries are well pronounced. The scar is saddle-shaped or has two short branches.

Fruits

The fruits are capsules that are available in an enlarging calyx, which is usually larger than the fruits, only in M. coccinea fruit and sepals are nearly the same length. The fruits have a long or short beak at the top. The pericarp is thick only in M. Crosbyana and coriaceous, in the other species it is thin and membranous. The fruits contain about 50 to 100 seeds, these are boomerang - or slightly curved to almost straight rod-shaped and 1.9 to 3.8 mm long. The embryo is 1.6 to 3.2 mm long and slightly curved. It has applied cotyledons, which are longer than they are wide and are shorter, but wider than the rest of the embryo. Endosperm is only very sparingly present.

Occurrence

Main distribution area of the species is the northern South America, where most species of the genus occur. They grow there in mountainous regions at altitudes of 500-3000 m, ten of species dominate the vegetation of the Andes of Colombia, Ecuador, Peru and Bolivia. Three species are endemic in Central America, four myrmecophilous species occur in the Amazon Basin and Guyana.

System

In the genus Markea 14 or 17 species are recognized, the three Central American species are placed in part to the genus Schultesianthus.

Selection of species:

• Markea crosybana D' Arcy ( syn. Schultesianthus crosbianus ( D' Arcy ) S. Knapp)
• Markea coccinea Rich.
• Markea formicarum Dammer
• Markea longiflorum Miers
• Markea lopezii Hunz.
• Markea sessiliflora Ducke
• Markea sturmii Cuatrec.
• Markea uniflora Lundell ( syn. Schultesianthus uniflorus ( Lundell ) S. Knapp)
• Markea venosa Standlschmaus. et C.V. Morton ( syn. Schultesianthus venosus ( Standl. et CV Morton ) S. Knapp)

The type species is M. coccinea.