Sunday, November 1, 2009

Petrocosmea minor Hybrids - First Flowers

It is always a happy day when a new Petrocosmea seedling flowers for the first time. Usually by that time, I have been able to study to foliar characteristics from the seedlings, but the flowers often show surprisingly high variation in color and characteristics. The latest cross to flower is P. sericea x minor veined leaf form. This is one of only two crosses I was able to get using P. minor and both crosses produced few seeds. In this cross, two plants with similar floral structure were used, and the closer relationship to each other within the genus may have been why this cross succeeded when others have not. Both P. sericea and P. minor exhibit flower structure that appears to place them in Section - Anisochilus, where the upper two petals are often reduced to one half the length of the lower three petals. The two upper petals are fused together into an upper lip or hood with two lobes. This flower form is also seen with the various forms of P. rosettifolia, P. sp. 'China-2005' and P.
cavaleriei and P. sp. 'HT-2' and P. sp. 'Yumebutai'.

The seedlings all show very uniform foliar characteristics, appearing much like a hairy leaf form of P. minor veined leaf. The cupping of the leaves, seen in P. sericea is only showing up in one seedling, so far. The flowers of the two seedlings which have flowered so far, show some variation between the two parents, with one flower looking more like P. sericea in color and form, showing no white in the throat. The second seedling looks more like the P. minor parent, and showing the white throat of this parent. Both seedlings show the promise of becoming quite large plants, and I will be potting them on into larger pans soon to allow them to develope more.

One characteristic that I am not liking in these seedlings is that they both have very long, wiry peduncles. I'll evaluate that in the next flowering with more maturity. If the plants do indeed grow into large rosettes, the longer peduncles may be necessary for the flowers to extend beyond the long petioles of the leaves in the rosette, so I am not too concerned yet. They peduncles do both show a nice wine-purple coloring.

The first seedling to flower from the cross of P. sericea x minor veined leaf form resembles P. sericea in flower form and color.

The second seedling to flower resembles P. minor veined leaf in flower form and color.

All of the seedlings have been quite uniform in foliage form, looking like a fuzzy leafed form of P. minor veined leaf form as can be seen in this seedling above.

The flower of Petrocosmea sericea - very similar in form to P. minor flowers. The two species are likely very closely related to each other. The two upper petals are fused into a two-lobed lip or "hood" to the flowers. Upper petal length is roughly one half the length of the lower three petals, and likely places these species in Section - Anisochilus, along with the plants labeled P. rosettifolia, whose flowers are very similar in shape.

The flower of Petrocosmea minor veined leaf form also share the flower form and structure of Section- Anisochilus with P. sericea..the other parent in this cross. In this form of P. minor, the leaves are deeply veined. This form also shows the veining in the lower petals of the flowers, which the other forms of P. minor do not have. The flowers of this form are a bit smaller and have a more pronounced clear white throat.