Passiflora lutea or Yellow Passionflower is the least ornamental of the Passiflora but the most northern and most cold resistant.
The plant dies when it freezes but resist to temperatures down to -15 °C and even briefly to -30 °C.
The flowers attract butterflies and are host to a specialist bee, anthemurgus passiflorae, which has the particularity that it does not pollinate the flower.
Passiflora lutea is a vine or creeper with nearly round tendrils of up to 3 m long which die annually when freezing.
The petiole is 1-5 cm long. Leaves are three-lobed, 2-10 cm long, 2.5-15 cm wide.
The petiole is 1.5-6 cm long, with 1 flower without bract or with microscopic bract. The flower is light yellow-green, 1.5-2 cm in diameter. Sepals are yellowish green, oblong, to 1.2 cm long and 0.3 cm wide. Petals are bright yellow-green to almost white, narrow oblong, to 0.8 cm long and 0.15 cm wide. The corona consists of two series of filaments. The outer serie is 0.5-1 cm long, filiform, light yellow or light yellow-green, usually violet at the base. The inner serie is about 0.2 cm long.
The fruit is almost spherical, up to 1.5 cm long and 1 cm wide, dark purple to nearly black when ripe. The seeds are obovate, about 0.4 cm long and 0.3 cm wide.
Passionflower, wild yellow Passion flower, yellow Passionflower
Passiflora lutea var. glabriflora
Passiflora: from the Latin passio (Passion) and flos (flower)
Lutea: from the latin lūteus (yellow)
North America: south central and east, between 0 and 1,000 m
USDA Zone 7-11, -15 °C and short periods of down to -30 °C
Fertile and well drained, grows on a variety of soils, except desert conditions
Water daily in summer if grown in pot
A small pot promotes flowering and prevents root growth
Seed, cutting, rhizome cutting
- use preferably fresh seeds
- scarify the seeds with sandpaper or sand
- soak the seeds in water at room temperature for 24h
- plant in potting soil, a 1 cm depth
- provide soil heating and switch the heating off at night so that the temperature fluctuates
- keep the substrate moist
- do not discard the seeds if they have not germinated after a few months, it can take more than 6 months
- uncover the underground rhizome
- cut off a piece of rhizome of 5-15 cm
- place the root cutting in a pot with light potting soil
- place in a warm place and keep the soil moist
- after 2 months the first new shoots appear