Saturday, 2 January 2010

January comment thread

For general comments and questions related to Malvaceae from anyone.


Peter Jack said...

I wonder if I could ask you about Lavatera oblongifolia please?
Seed is available from 'Rare Plants' and I was impressed by the flower picture.
Coming from southern Spain, do you think it would be worth trialing as a garden plant - or perhaps brought into a greenhouse over winter? Does it have the same growth habit of L. maritima?

You may be interested to see the image of a form of L. maritima from Majorca on the same website.
The flower has a purple centre, but no veining.

P.g. Jack

Anonymous said...

I'm not sure if this blog is still active but wanted to thank you for your detailed website.
It has enabled me to identify what I now believe to be a Corynabutilon x suntense, possibly ‘White Charm’, in my garden in Surrey, England.
Many thanks!

Lavateraguy said...

I don't have any experience with Lavatera oblongifolia, but I would guess that it might need winter protection.

I find that Lavatera maritima is on the borderline of hardiness, and lost all my mature plants last winter. (I overwintered cuttings on windowsills.) The same holds for another Mediterranean Lavatera - Lavatera olbia

I'm pretty sure that Lavatera maritima as grown in the UK is a single clone - if you look on the web you see some variety in the flowers. I would think that it would be worthwhile introducing other clones if they were sufficiently hardy.

Bill said...

I'm a hobbyist breeder and have had success crossing H. rosa-sinensis but can't seem to get the seedlings to flower. Can you point me towards research and/or publications related to forcing the plants to flower? Any help you can provide would be greatly appreciated.

Best regards,

Lavateraguy said...

I don't have knowledge of this myself. I would second Steven Hill's recommendation of the International Hibiscus Society, and there is also a Tropical Hibiscus Mail List.

However, how old are your plants? Shrubs can take some time to reach flowering size, so it's possible that you just have to be patient.

Anonymous said...

Is this blog a good place to discuss
Hibiscus hybridization? I'm specifically interested in section
Bombicella x Calyphylli. Anyone who
is doing this or records of success
in this area.

Lavateraguy said...

Probably not a helpful place for discussing Hibiscus hybridisation; I suspect that my readership is very small.

Hibiscus is a very genetically diverse genus, and I wouldn't expect intersectional crosses to be successful in general.

However, an Indian group apparently managed to cross a Hibiscus with a cotton (link), so the possiblility of wide hybrids cannot be absolutely excluded.

The only intersectional hybrids that I know of in Hibiscus are between Hibiscus mutabilis (section Venusti) and North American species of section Muenchhusia (both part of section Trionum sensu lato).

Section Calyphylli is distant from Bombicella (link); at first sight you would have a better chance of crossing Bombicella with the hardy shrub or tropical hibiscuses.

The International Hibiscus Society (link) mailing list may have something to say.

Anonymous said...

As I suspected my seedlings are selfs or apomicts. said...


I found a single mystery naturalized Malva in San Marcos (San Diego County, California). The closest I can key it is M. pseudolavatera (syn. Lavatera cretica), but it doesn't quite look like other naturalized M. pseudolavatera I have seen. I also have M. nicaeensis growing in my yard and it doesn't fit that species either. I realize that you need to see the plant, but the plant has now dried up and gone to seed.

I will make herbarium specimens from the seeds I am growing.

My image page for this plant is at the followinglink:

1. Based on the bractlet width, about the only name I can come up with is M. pseudolavatera, although the faint veins and flower size resemble M. neglecta. The fruit sections are probably too immature to be certain, but they appear to be smooth, not net-veined or cross-ridged on back.

2. Could this be an impoverished or perhaps a variant of M. pseudolavatera?

3. Could this be a fertile hybrid, possibly between M. parviflora & M. pseudolavatera?

3. Malva pseudolavatera is listed in the new revised Jepson Manual of California Plants, but is still "not resolved" in the Kew Plant List. I am curious why it is still unresolved?



Lavateraguy said...

2: Apart from the decumbent habit I don't see any reason to discount Malva pseudolavatera, and the habit might be due to removal of the leader. (In my experience Malva sylvestris goes decumbent on mown grass verges; Malva neglecta is naturally decument. Well grown Malva sylvestris x durieui is erect but develops recumbent side shoots.)

But I don't recall how much ornamentation mature mericarps develop.

You could try asking Christopher Davis (now at the Desert Botanical Garden in Phoenix); he's been working on this group.

3A: The general rule with hybrids in Malva seems to be that hybrids with different ploidies are sterile, and hybrids with the same ploidy are fertile.

Malva pseudolavatera seems to be (the only) hexadecaploid (2n=112) (assuming the old 2n=42 counts are based on misidentified specimens), and hence its hybrids might be expected to be sterile. (From my own experience Malva sylvestris x pseudolavatera is sterile, with a seed set of ~0.1%.)

Hence I doubt that it is a hybrid involving Malva pseudolavatera.

3B:The Plant List is only a reliable source for some taxa (e.g. monocots and palms); for Malvaceae it's basically a copy of Tropicos's incomplete data set.

My World Checklist of Malvaceae (link) is better, but there are still bits of the world for which data is difficult to find. said...

Thank you for comment about Malva pseudolavatera.

Do you know of a more extensive key to Malva of Eurasia or possibly a world key?


Lavateraguy said...

Try Flora Europaea or Flora Iberica (but in both cases you would have to take into account the placement of several species in Lavatera). Flora Iberica is online.

IIRC, the only widely accepted taxa which are present in Eurasia, and not in Europe, are Malva(lthaea) transcaucasica and Malva (Althaea) ludwigii.

Spain has the greatest diversity, and Flora Iberica gives fulls descriptions of the Spanish taxa.

Peter Jack said...

I just wanted to (very belatedly) thank you for your advice on L. oblongifolia. I did not see it until today.
It has not flowered yet. In a pot, it seems to be very easy to over- and under-water, often dropping all its leaves, so I will plant it in a sunny spot in the garden, and just hope for the best.