D. capillaris or D. rotundifolia

[jimscott]

I'm trying to discern the difference between D. capillaris and D. rotundifolia. I have a colony of D. capillaris:

and I have a stray sundew among a colony of U. dichotoma (no picture as yet). I can't tell the difference. I've read the difference in CP's of the World and it describes the leaf blades as being longer than they are wide and D rotundifolia as having leaf blades broader than they are long. A color photo in the book shows a D. rotundifolia with a long, thin leaf, which doesn't look consistent with what I am reading. I did some searching in the Humboldt site and I see plants with both thin and wide leaves as being D. capillaris. Can someone straighten me out?

 

[Not a Number]

I always struggle with D. intermedia vs D. capillaris vs D. rotundifolia although I'm getting better at it. The seeds are surest way to tell. Otherwise I just go through the species descriptions checking off the characteristics. You start to memorize them eventually.

I think the biggest difference other than the shape of the leaves is that D. rotundifolia has flatter, slightly more hairy petioles. D. capillaris has a more oval cross section on the petioles.

http://www.omnisterra.com/botany/cp/pictures/drosera/0077.htm#D.capillaris

They're looking good. No flowers?

 

[jimscott]

2. Drosera rotundifolia

2. Drosera rotundifolia L. Petioles 1.5-5 cm. long, flat, glandular-pilose. Leaf-blades 4-10 mm. long, broader than long and much shorter than the petioles. Stipules 4-6 mm. long, adnate, fimbriate along the upper half. Scape glaborous, 7-35 cm. long, bearing 3-15 lowers 4-7 mm. in diameter. Sepals oblong, 4-5 mm. long, obtuse. Petals white to pink, spatulate, longer than the sepals. Seeds light brown 1-1.5 mm. long , sigmoid-fusiform, finely and regularly longitudinally striate, shining with a metallic luster.


6. Drosera capillaris

6. Drosera capillaris Poir. Petioles 0.6-4 cm long, sparsely glandular- pilose. Leaf-blades broadly spatulate, 5-10 mm. long, 3-5 mm. wide, usually shorter than the petioles. Stipules free, or adnate for the first millimeter, then breaking into numerous setaceous segments 3-5 mm. long. Scape glabrous, 4-20 cm. long, Bearing 2-20 flowers. Flowers pink, 10 mm. wide. Sepals oblong-elliptic, 3-4 mm. long, obtuse. Petals 6-7 mm. long. Capsule 4-5 mm. long, surpassing the calyx. Seeds brown, elliptic to oblong-ovate, 0.4-0.5 mm. long, asymmetric, coarsely papillose-corrugated in 14-16 ridges.

I just copied and pasted the two in question. I've seen what I think are conflicting and confusing pictures on the Humboldt site. But maybe that's just me. Reading these descriptions illustrates to me that I need to learn another language! I have to find a metric ruler amongst the ruins of the kids' room and look up a few words - like papillose, pilose, and adnate.

No flowers yet. Those plants are from what you sent and they definitely look happy.

Oddly enough, the whole reason why and how I found the discussion forums was because I wanted an ID for a colony of sundews I bought at a local nursery. Savage Garden and CP's of the World, which I found at Barnes & Noble and Borders were helpful but not conclusive. I had the colony narrowed down to D. spatulata, intermedia, rotundifolia, and capillaris. So I did a search on the Internet and found somebody's picture that really looked like mine. It turned out to be D. spatulata and the process of searching resulted in stumbling across the discussion forums.

Here are some pics of D. capillaris from the site:

http://www.bestcarnivorousplants.org/fotogalerie/sr50-688.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-690.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-698.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-708.html

And here are some D. rotundifolia:
http://www.bestcarnivorousplants.org/fotogalerie/sr50-1033.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-1046.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-1034.html

http://www.bestcarnivorousplants.org/fotogalerie/sr50-1026.html

 

[jimscott]

Okay, after confirming the one is D. capillaris, I now have D. rotundifolia. Here they are, now, side by side: