|
36. Amitostigma Schlechter, Repert. Spec. Nov. Regni Veg. Beih. 4: 91. 1919.
无柱兰属 wu zhu lan shu
Authors: Xinqi Chen, Stephan W. Gale & Phillip J. Cribb
Mitostigma Blume, Mus. Bot. 2: 189. 1856, not Decaisne (1844).
Herbs, terrestrial, slender. Tubers subglobose to ovoid, undivided, fleshy, neck with several slender roots. Stem erect, 1- or occasionally 2-leaved, glabrous or occasionally pubescent. Leaves basal or cauline, usually green and unspotted, rarely with purple-brown blotches, oblong, lanceolate, elliptic, or ovate, base contracted into amplexicaul sheath. Inflorescence a terminal raceme, glabrous; peduncle elongate, with 1 or more sterile bracts; rachis 1- to several flowered. Flowers often secund, resupinate, white, pink, mauve, or purple, rarely yellow; ovary usually straight, twisted, shortly pedicellate, cylindric-fusiform, glabrous. Sepals free, oblong to ovate, 1-veined. Petals free, often connivent with dorsal sepal and forming a hood, usually wider than sepals; lip spreading, spurred at base, 3-lobed; disk often papillose; mid-lobe often divided, forming 2 lobules; spur cylindric to narrowly conic, short to elongate. Column very short; anther usually erect, oblong-ellipsoid to obovoid, 2-locular, locules parallel or slightly divergent; pollinia 2, oblong, sectile, granular-farinaceous; caudicles straplike; viscidia naked, oblong-ovate; rostellum rather small, 3-lobed, base with ± ascending arms on both sides, margin adnate to column; stigma ventral, 3-lobed, lobes confluent, relatively large, flat to somewhat raised; auricles 2, large, stout, placed laterally at base of anther. Capsule suberect.
About 30 species: E Asia and adjacent areas; 22 species (21 endemic) in China.
The generic affinity of several of the entities presently referred to Amitostigma remains questionable and in need of re-examination; many of the endemic Chinese taxa are poorly known.
|
|
|
|
| 1 |
Plants 2-leaved (A. alpestre rarely 1-leaved) |
|
(2) |
| + |
Plants 1-leaved |
|
(7) |
| |
|
|
|
| 2 (1) |
Leaves cauline, widely spaced |
|
(3) |
| + |
Leaves basal, subopposite |
|
(4) |
| |
|
|
|
| 3 (2) |
Lip obovate, 3-lobed near middle, 4.5-5.5 mm wide, longer than broad; lateral lobes ovate-oblong, ca. 0.5 mm wide; spur 4-4.5 mm. |
|
17 A. alpestre |
| + |
Lip orbicular to transversely elliptic, 3-lobed toward apex, ca. 8.5 mm wide, broader than long; lateral lobes quadrate, ca. 2.5 mm wide; spur 5-7 mm. |
|
18 A. yuanum |
| |
|
|
|
| 4 (2) |
Rachis 1-flowered. |
|
19 A. papilionaceum |
| + |
Rachis 3- to more than 10-flowered |
|
(5) |
| |
|
|
|
| 5 (4) |
Leaves usually appressed to substratum; petals ca. 5 × 3 mm; lip ca. 9 mm. |
|
22 A. physoceras |
| + |
Leaves erect to porrect; petals 3-3.5 × 1.5-2 mm; lip 4.5-6 mm |
|
(6) |
| |
|
|
|
| 6 (5) |
Lip 3-lobed below middle; lateral lobes linear. |
|
20 A. bifoliatum |
| + |
Lip 3-lobed above middle; lateral lobes ovate. |
|
21 A. wenshanense |
| |
|
|
|
| 7 (1) |
Leaf appressed to substratum, adaxially with purplish brown blotches. |
|
1 A. hemipilioides |
| + |
Leaf erect or porrect, uniformly green |
|
(8) |
| |
|
|
|
| 8 (7) |
Rachis 1- or rarely 2-flowered |
|
(9) |
| + |
Rachis usually 3- or more flowered (A. faberi rarely 1- or 2-flowered) |
|
(15) |
| |
|
|
|
| 9 (8) |
Spur 8-17 mm, ca. as long as to exceeding ovary |
|
(10) |
| + |
Spur 2-4 mm, usually much shorter than ovary |
|
(12) |
| |
|
|
|
| 10 (9) |
Lip 3-lobed toward apex, 11-15 × 13-19 mm; lateral lobes broadly oblong-ovate, ca. 5 mm wide. |
|
6 A. pinguicula |
| + |
Lip 3-lobed below middle, 8-10 × 6-10 mm; lateral lobes linear-oblong or ovate-triangular, 1-3 mm wide |
|
(11) |
| |
|
|
|
| 11 (10) |
Dorsal sepal 4-5 mm; spur 11-12 mm. |
|
7 A. dolichocentrum |
| + |
Dorsal sepal ca. 7 mm; spur 8-9 mm. |
|
8 A. tibeticum |
| |
|
|
|
| 12 (9) |
Stem densely pubescent around leaf base; floral bract much shorter than ovary; lip 5-6 mm. |
|
2 A. amplexifolium |
| + |
Stem glabrous; floral bract nearly as long as to exceeding ovary; lip 7-15 mm |
|
(13) |
| |
|
|
|
| 13 (12) |
Flower yellow. |
|
3 A. simplex |
| + |
Flower pale purple, pink, or white |
|
(14) |
| |
|
|
|
| 14 (13) |
Leaf 0.1-0.4 cm wide; petals broadly ovate, 4.5-5.5 mm wide. |
|
4 A. farreri |
| + |
Leaf 0.6-1 cm wide; petals ovate, 1.6-2 mm wide. |
|
5 A. monanthum |
| |
|
|
|
| 15 (8) |
Mid-lobe of lip 4-7 mm wide, nearly as broad as to broader than long |
|
(16) |
| + |
Mid-lobe of lip 0.5-3.5 mm wide, much longer than broad |
|
(18) |
| |
|
|
|
| 16 (15) |
Ovary and pedicel 15-25 mm; dorsal sepal ca. 7 mm; lip ca. 13 mm. |
|
16 A. gonggashanicum |
| + |
Ovary and pedicel 6-10 mm; dorsal sepal 2.5-3.5 mm; lip 5-7.5 mm |
|
(17) |
| |
|
|
|
| 17 (16) |
Peduncle ebracteate; spur 2-3 mm. |
|
14 A. basifoliatum |
| + |
Peduncle with 1 sterile bract; spur 5-6 mm. |
|
15 A. faberi |
| |
|
|
|
| 18 (15) |
Mid-lobe of lip ca. 3.5 mm wide, deeply divided above middle to form 2 distinct lobules. |
|
9 A. parceflorum |
| + |
Mid-lobe of lip 0.5-2 mm wide, apex truncate, obtuse-rounded, occasionally emarginate or shallowly notched |
|
(19) |
| |
|
|
|
| 19 (18) |
Lateral lobes of lip oblong-obovate, 1.6-2 mm wide; spur 3.5-6 mm. |
|
10 A. tetralobum |
| + |
Lateral lobes of lip lanceolate, linear-oblong, ovate-oblong, or triangular, 0.3-0.8 mm wide; spur 1-2.5(-3.5) mm |
|
(20) |
| |
|
|
|
| 20 (19) |
Peduncle ebracteate; flowers white; mid-lobe of lip ca. 1.6 mm. |
|
11 A. capitatum |
| + |
Peduncle with 1 or 2 sterile bracts; flowers pink, rose-pink, purplish red, or purple; mid-lobe of lip 2-4 mm |
|
(21) |
| |
|
|
|
| 21 (20) |
Plants 7-25 cm tall; leaf usually basal; lip 3-lobed above middle. |
|
12 A. gracile |
| + |
Plants 24-36 cm tall; leaf cauline; lip 3-lobed below middle. |
|
13 A. trifurcatum |
|
|
|
List of lower taxa
| Related Links (opens in a new window) |
|
Treatments in Other Floras @ www.efloras.org
Other Databases
|
|
|
|
|
|
|
