Showing posts with label Perennial. Show all posts
Showing posts with label Perennial. Show all posts

Thursday, April 19, 2012

Thumbnail guidelines on growing a tropical pitcher plant



  • Nepenthes x superba
    Nepenthes ×superba
    (lower pitcher)
  • Nepenthes x superbaNepenthes ×superba
    (upper pitcher)
So, you have a Nepenthes, huh? Not quite my recommendation as a first carnivorous plant for the beginner to try. The challenge is that these plants can be really big, and so require really large growing areas. They don't usually tuck into a small terrarium very conveniently.

Let me suppose that you bought a small plant. By small, I mean a plant that occupies about as much area as your hand, with your fingers splayed. In this case, growing the plant is pretty easy. Unlike most carnivorous plants, Nepenthes do not require super bright light. So it might actually survive on a very bright windowsill. But it does like the light it would get from a bright terrarium, so don't hesitate to consider rigging up a carnivorous plant terrarium as I describe elsewhere in the FAQ. Even a bottle terrarium will be helpful if your plant is small enough.

Nepenthes plants do not like to be sitting in water, so put your little potted plant in a shallow saucer and water it every day or so---however often you find it necessary to keep the potting medium moist. If you keep it sitting in water, the root system will become dwarfed (at least for most species) and the plant will be small in general. They like conditions humid and warm. Never give them a winter dormancy, as they are tropical plants that grow year-round. If you must transplant them, put them in a mix like 50:50 Sphagnum:perlite.

Nepenthes like very high humidity, around 70-100%, so you'll need to keep it in some kind of humidity enclosure like one of the terrarium options I mentioned above.

If, for some fool reason, you have yourself a very large plant, you're going to have a devil of a time finding a place you can keep it. It will need lots of light, and plenty of humidity. Follow the same guidelines as for small plants---don't let it sit in water, but keep the soil moist. How you're going to achieve all this in a conventional house, I don't know. You really need a greenhouse.

If you try growing Nepenthes, but don't do it very well, the plant will probably survive fairly well, but might just look like a lanky vine. The pitchers the plant had when you bought it will eventually die, and the new leaves that form won't make replacement pitchers. This is very frustrating, I know. What must you do to have a plant make pitchers? Just grow the dang thing better. Pitcherless leaves, by itself, is such a general symptom that it can't be used to diagnose exactly what you're doing wrong.

If you have a Nepenthes plant and really want it to grow, I recommend you buy a book like D'Amato. That will cover all the extra stuff like fertilizing, propagation, etc.

Finally, if for some reason you have a hair up your bum to grow Nepenthes rajah as your first plant, take a pill or something. This is a very expensive plant with particular needs, and is suitable only for the expert.

What do you mean by "absorption pathways?"



  • Sarracenia purpurea
    Sarracenia
    purpurea
  • Pinguicula primulifloraPinguicula
    primuliflora
  • Utricularia dimorphanthaUtricularia
    dimorphantha
  • Drosera glanduligeraDrosera
    glanduligera
This is the third attribute of a carnivorous plant:

A pathway is available that allows nutrients to be absorbed into the plant, thus contributing to the plant's competitive and reproductive fitness. For most carnivorous plants, nutrients are transmitted via diffusion through trap fluids. In some cases (i.e., Roridula), nutrients are first passed through the digestive tracts of mutualistic organisms and then deposited, as fecal matter, onto the leaves, whereupon they enter the plant through cuticular gaps.

The nutrients pass into plants by three mechanisms, depending upon the plant.
  1. Some plants have specialized cells or cellular structures to allow for the absorption of nutrients. Examples include the stalked or sessile glands of Drosera or Pinguicula, or the quadrifid glands inside the bladders of Utricularia.
  2. Nutrients may enter the tissues directly. The interior pitcher walls of Sarracenia lack the waxy protective layer called a cuticle. This allows the nutrients from the pitcher fluids to enter the plant.
  3. Nutrients may enter the tissues through specialized gaps in the cuticle. In Roridula, breaks in the cuticle allow the nutrients from hemipteran fecal matter to enter the plants. Cuticular gaps are a big liability for plants because they expose the plant to dehydration or invasion by pests and disease, so a plant will not have such gaps unless they confer a real benefit to it.
Did you notice that, in my definition, I note that the nutrients must confer a benefit to the plant? This is important because it is the evolutionary drive behind selecting for carnivory. Plants will not evolve to be carnivorous if there is plenty of food present for it in the soil! For this reason, I don't think we will ever discover a carnivorous plant that occurs in rich, fertile soils.

Wednesday, June 23, 2010

Plant of the day - Pinguicula Primuliflora

Perennial herb. The leaves are in basal rosettes that are 4-16 cm broad. The leaves are bright green, oblong, rounded at the tip, 6-9 cm long, 2.0-2.5 cm wide, and covered with short, knob-tipped (sticky and glandular) hairs. The flowers are solitary on leafless stalks (scapes) that become 8-15 cm tall, and have scattered, short, knob-tipped hairs. The flowers are bilaterally symmetrical with the calyx 2-lipped, the upper lip with three distinct lobes and the lower lip with two smaller lobes (see persistent calyx around fruit in illustration). The corolla consists of an expanded portion that is 2.5-3.0 cm wide with five nearly equal lobes that are obovate to nearly round, 8-13 mm long, 10-14 mm wide, and shallowly notched; a narrow tube that is 4-5 mm long; and a narrow, basal, downward extension or spur that is 3-5 mm long. The corolla tube and spur are lemon yellow with prominent brownish-violet veins; the ground color of the expanded portion of the corolla varies from deep to pale bluish-violet with darker veins, with a ring of white at the throat and a mass of yellowish, sometimes reddish-tipped, club-shaped hairs at the center. Some of these hairs, besides occurring along the inner throat, are found on an appendage (palate) that projects obliquely some 3-5 mm from the lower, inner surface of the corolla tube. The two stamens are white; the single ovary has a white style with two unequal lobes. The fruit is a rounded capsule, 5 mm in diameter, with numerous seeds. The seeds are brown, small (0.5-0.7 mm long), somewhat broadened at one end, and honeycomb-surfaced.