Studies in Neotropical Apocynaceae LIV: a synopsis of Asketanthera
Author
Morales, J. Francisco
text
Candollea
2018
2018-03-27
73
1
7
17
journal article
3533
10.15553/c2018v731a2
ea73ea53-7e6c-4e4e-8260-7da383dffc67
2235-3658
5683677
Asketanthera
Woodson
in Ann.
Missouri
Bot. Gard. 19: 46. 1932.
Typus
:
Asketanthera calycosa
(A. Rich.) Woodson.
Lianas,
young stems herbaceous, becoming more or less woody with age; branchlets cylindric to subcylindric, with milky sap, pubescent to glabrate; interpetiolar colleters very small.
Leaves
opposite, petiolate, petioles without colleters, blades glabrous, glabrescent or variously pubescent, membranaceous, without colleters or domatia, not revolute.
Inflorescence
axillary, a few- to many-flowered cyme, usually variously pubescent, pedunculate, bracts foliaceous, well developed.
Sepals
5, foliaceous, prominantly nerved, all more or less the same size and shape or subequal, free, with a single entire to variously lacerated colleter at the base of the adaxial surface.
Corolla
hypocrateriform with the indument distributed on five longitudinal lines, without corona or free corona lobes, the limb actinomorphic, 5-lobed, dextrorsely contorted.
Stamens
5, included, anthers connivent and agglutinated to the style-head, anthers glabrous, the base auriculate, the auricles rounded to acute, filaments short, pubescent.
Carpels
two, united at the apex, style-head with a basal expanded ring.
Ovules
many, several-seriate; nectaries 5, each nectary lobed or entire, glabrous.
Follicles
2, apocarpous, free, often remaining united at the tips for some time, dehiscing along the ventral suture, terete or subterete, membranaceous, continuous, pubescent to glabrate; seeds numerous, dry, rostrate, glabrous to sparsely pubescent, comose at the microphylar end.
Distribution
. – Four species restricted to
Cuba
and Hispaniola (
Dominican Republic
and
Haiti
).
Fig. 1. –
Asketanthera calycosa
(A. Rich.) Woodson.
A.
Habit
;
B.
Adaxial view of two sepals, showing the colleters at the base;
C.
Corolla
bud;
D.
Anther, dorsal view;
E.
Style-head;
F.
Nectaries and ovary;
G.
Follicles;
H.
Seed.
[
A-F:
Figueiras 197,
US
;
G-H:
Eggers 4707,
US
] [Drawings: J.F. Morales]
Fig. 2. –
Asketanthera dolichopetala
(Urb.) Woodson.
A.
Habit
;
B.
Adaxial view of one sepal, showing the colleter at the base;
C.
Corolla
bud;
D.
Anther, dorsal view;
E.
Style-head, nectaries, and ovary.
[
Fuertes 453,
S] [Drawings: J.F. Morales]
Key to the species of
Asketanthera
1. Corolla tube
63-80 mm
; inflorescences 2-4-flowered; anthers
11-14 mm
long.............................. 3.
A. longiflora
1a. Corolla tube
11-21 mm
; inflorescences 8-20-flowered; anthers
5.5-7 mm
long.................................................... 2
2. Petioles
12-20 mm
; peduncles (30-)
35-55 mm
long......... ...............................................................2.
A. dolichopetala
2a. Petioles
4-10 mm
; peduncles
4-20 mm
long...................3
3. Corolla tube
11-15 mm
with lobes
9-15 mm
; leaf blade with the base acute or attenuate.................. 4.
A. picardae
3a. Corolla tube
15-21 mm
with lobes
28-41 mm
; leaf blade with the base obtuse to rounded ................. 1.
A. calycosa