Afrikanische Genlisea

[Andreas Fleischmann]

Hallo zusammen!

Ich verspreche, diesen Text noch frei ins Deutsche zu übersetzen, aber momentan bin ich dazu etwas zuschläfrig. Aber es soll mir ja keiner nachsagen, ich würde die englischsprachigen Karnivoren-Foren bildertechnisch bevorzugen!

Alles Gute Nacht,

Andreas

After this year's botanical expeditions to Sierra Leone, Zambia and South Africa, I know have enough photographs of Genlisea in the wild to provide a little picture guide of the confusingly similar African species of Genlisea.

Unfortunately, we did not see G. pallida, G. taylori and G. angolensis in Zambia, but all of these grow in the south western part of that country, very close to the Angolean border. And I simply was not able to convince Fernando to go hunting for CPs in an area covered by landmines...

Most of the African species of Genlisea look somewhat similar, and most of them are blueish to purple in flower.

There are two species that have a totally glabrous stem, and the sepals (the calyx) and ovary (i.e. later the seed capsule) are not covered by glands, but only by simple hairs (or they are even glabrous, too). These are the well-known G. hispidula and its close relative G. subglabra. See below.

In all other African Genlisea, the stems are more or less densely covered by secreting glands, same is the calyx and the ovary. For the identification of these species, very doubtful characters have to be considered: The length and distribution of glandular versus non-glandular hairs on calyx and ovary and the relative length of the nectar spur compared to the lower lip of the flower.

If you had a species of Genlisea from Africa that bears glands on its flower stalk first look at the ripe fruits:

Are the fruiting pedicels strongly decurved (i.e. is the seed capsule bend towards the stem)? Or are the ripe fruits held erect?

If they are decurved, you can select between 3 species, if they are erect, 5 species are remaining.

Pedicel bend downwards in fruit:

Flowers are cream or whitish, leaves are elongated and arranged in a somewhat loose rosette: G. pallida. No photos, soory. AFAIK, this plant is NOT in cultivation yet! (Any corrections??) All plants labelled as "G. pallida" in cultivation are falsely identified G. filiformis.

Let's say the plant has a long flower stalk, more than 15 cm in length, and the glands are mainly distributed in the upper part, where the flowers are (the base of the flower stem is glabrous). The upper lip of the flower has a constriction at its base. The lower lip appears to be entire or is only shallowly lobed. That's G. margareatae.

Fernando and I found this plant even at the type location of G. margaretae. This plant has dark purple flowers and very long flower stalks, up to 40 cm in lenght. Like the plants from Madagascar, which are common in cultivation now, it forms dense and compact rosettes of short leaves, juvenile rosettes are produced on stolon-like trap leaves and emerge from the soil near the mother plant. The plants from Madagascar which had been introduced to cultivation have brighter coloured flowers on shorter stalks.

If the plant had numerous very glabrous scapes emerging from one rosette, which are shorter than 15 cm in height, and if the lower lip of the flower was distinctly 3-lobed, then it's Genlisea glandulosissima ("the most glandular Genlisea"). The name was chosen correctly for that plant!

What a CP garden! G. glandulosissima growing together with D. madagascariensis, D. burkeana (dead, brown rosette), G. africana, U. welwitschii 'purple flowers' (in front), my favourite U. subulata (you'll see a lot of photos of that one soon! ) and the pipewort Syngonanthus (Eriocaulaceae).

Note the deeply trilobed lower lip of the flower and the dense cover with long sticky glands. We found several small insects sticking to the flowerscapes of that Genlisea. You can well imagine how Pinguicula evolved from Genlisea-like ancestors.

Now for those Genlisea that have glands on flower stem and which do not bend down the ripe fruits:

In case the sepals bear glands:

If the pedicels are only covered by short stalked glands, it's G. africana.

This plant has thin, filiform flower stalks which are often branched several times. Flowers can be dark purple to mauve or even cream white.

G. africana might grow as an annual in some habitats (like on grantic inselbergs), but we found it growing as a facultative perennial in bogy seepage habitats in Zambia. It was growing in places rich in other CPs, like Drosera burkeana, D. affinis, D. madagascariensis, G. margaretae, G. glandulosissima and many species of Utricularia.

A strange white flowered form with a green tip of the spur had been describe as "Genlisea subviridis" by Hutchinson in 1946, but it was reduced to synonymy of G. africana by Taylor later. In my opinion this plant deserved to be a species of its own! Hutchinson was right to separate it from G. africana! Look at the broad, strange spur! There are some more characters distinguishing it from odd G. africana...

Look at this spur!

Like in G. africna, the pedicel is only covered with glandular hairs, and the capsule is entirely covered by glands as well.

Habitat of G. subviridis in Zambia. That's how many CP sites look there. In the back you can see our car, a 4x2 ISUZU offroad, which Fernando almost wrecked by driving

Pedicels covered by glandular and smaller non glandular hairs:

The spur is much longer than the lower lip of the flower, the capsule is covered by long stalked glands only in its upper part (black arrow), the lower part is glabrous (see white arrow. The glands visible in that area are on the calyx, NOT on the ovary! ). Thus the ovary looks like a partially shaved gooseberry!

This is Genlisea barthlottii, a species of tropical western Africa.

It grows as an annual on granitic outcrops (inselbergs) in tropical west Africa. So far, it only had been known from a few locations in Guinea, but I found it growing on an inselberg in Sierra Leone as well.

The spur of G. barthlottii is clearly longer than the lower lip of the flower.

In the related G. stapfii the spur is shorter or only slightly longer than the lower lip of the flower, the ovary is covered by short glandular hairy all over. Sorry, no photograph of the ovary, but it looks like the capsule of G. africana shown above.

G. stapfii is another annual species of western Africa. I found it growing on an inselberg in northern Sierra Leone, together with U. pubescens, U. subulata and Drosra indica.

G. stapfii was treated as as synonym of G. africana for a long time. But the fact that in G. stapfii, eglandular and glandular hairs are found on the pedicel was reason enough to separate it from that G. africana again (which only bears glandular hairs). Whatever...

Two species with a glandular stalk are still missing: Both have no glands on their calyx. G. angolensis has a calyx densely covered by simple, non- glandular hairs (like in G. hispudula!), the calyx of the newly described G. taylori is totally glabrous or bears only a few glands at the very base.

Now for the 2 species that have no glands on their flower stalks at all:

If there are hairs on the capsule, it's G. hispidula (that's the origin of it's specific name!). The upper lip of that species is broad and round.

Fernando and I found G. hispidula growing in a seepage habitat near Pretoria, in the northern part of South Africa.

They grew in peaty soil or in sphagnum amoung reeds, grasses and sedges, together with Drosera longiscapa and a small, dark brownish-purple flowered form of U. welwitschii.

Note the densely hairy calyx! But it's simple hairs, they do not have a glandular tip.

The seed capsule is covered with these hairs as well.

If the capsule is glabrous, or has a few hairs on its very tip only, it's G. subglabra. In this species, the upper lip of the flower is narrow and has a even narrower tip. Christian Klein sold a plant labeled as "G. africana" which he obtained from Botanical Garden Bonn, Germany some time ago. These plants and their offspring which are now thriving well in some CPer's collections already are not africana, but G. subglabra!

The flower stem and pedicels of G. subglabra are all glabrous.

Can you see the narrow long tip of the upper lip which distinguished this species from G. hispidula?

At one location in Zambia, we found G. subglabra growing together with Drosera elongata. The Genlisea was growing submerged in a whole filled with water and it used the climbing stem of D. elongata to support its flower stem. The leaves of that Genlisea where hughe, more than 10 cm in length!

All the best,

Andreas

PS: In case the mix of key and photographs is too confusing, I can divide it into 2 seperate confusing threads if you liked.

[Markus Welge]

Hallo Andreas,

fantastische Bilder! Endlich bekommen wir mehr Klarheit über die verschiedenen afrikanischen Arten, von denen die meisten bisher nur aus Zeichnungen bekannt waren.

Genlisea subviridis gefällt mir besonder gut, da sie sich deutlich in Form und Farbe von den anderen unterscheidet.

Bei der Pflanze, die wir als Genlisea subglabra kultivieren, bin ich mir jedoch nun nicht mehr so sicher, ob die Bestimmung korrekt war. Hast du zufällig auch Fotos von der Blattrosette?

And I simply was not able to convince Fernando to go hunting for CPs in an area covered by landmines...

Das sollte einen echten CP-Hunter doch nicht abhalten ;-)

PS: In case the mix of key and photographs is too confusing, I can divide it into 2 seperate confusing threads if you liked.

Vielleicht könntest du einen Beitrag pro Art erstellen, es sind in der Tat sehr viele Bilder.

Viele Grüße

Markus

[Stefan Kuhlmann]

Hallo Andreas.

Ganz tolle Bilder!

Gebe Markus recht: So sieht man Arten, die man auf Fotos bisher nicht gesehen hat.

Und wieder was neues dazu gelernt! *freu*

[Denis Barthel]

Wie immer bei Andreas' Habitatphotos eine sehr beeindruckende Fotogalerie, in der Tat!

@Andreas: Du hast geschrieben "You can well imagine how Pinguicula evolved from Genlisea-like ancestors.". Ich dachte immer, die Pinguicula wären die ursprünglichste Gattung der Familie und auch am nächsten am gemeinsamen Vorfahren? Oder habe ich da etwas falsch verstanden?

@Markus: Das was ich bei mir als G. africana oder G. subglabra habe, ähnelt meiner bescheidenen Meinung nach verglichen mit den Photos am ehesten G. subglabra, insbesondere der im Vergleich zu G. africana schmalere Sporn, der an der Spitze schmutzig-gelb ist. Es wäre aber wirklich interessant, wenn Andreas noch etwas zu dieser Pflanze sagen könnte.

Gruß,

Denis

[Markus Berg]

Hallo Andreas,

vielen Dank für die fantastischen Fotos und den informativen Bericht. Ich selbst habe zwar nur wenige Genliseen in Kultur, aber diese Arten sind es sicherlich wert, kultiviert zu werden.

Viele Grüße

Markus