Flora of Dominica, Part 2 - Smithsonian Institution Libraries

NUMBER 77 ULM ACEAE-URTICACEAE 219
Trema micranthum
Trem micronthum (Linnaeus) Blume, 1856,2:58.-Grisebach, 1860:150.
Rhur micronthur Linnaeus, 1759a:937.
Celtis mollis Humboldt & Bonpland ex Willdenow, 1806,4:9%.
Sponk mollis (Willdenow) Decaisne, 1834498.
Sponk microntho (Linnaeus) Decaisne, 1834:498.
Trem molle (Willdenow) Blume, 1856,2:58.-Grisebach, 1860:150.
Shrub or tree to 3 m; leaves rather large, unequal at base;
fruits turning orange.
Neotropics; occasional in Dominica in dry areas: ridge north
of Clarke Hall (Ernst 1530), ridge south of Clarke Hall (Stern
& Wasshausen 2423), Hungry Hill (Whitefoord 4426), “inner
Cabrite of Prince Ruperts Head. Dominica. 25 June 1792”
([Finlay] s.n. at K), Trafalgar road (Whitefoord 4646), sine loc.
(Imray 467 at K). Flowering May-July, fruiting in November.
URTICACEAE
1. Leaves opposite ................... Pilea
1. Leaves alternate.
2. Inflorescences elongate or branching.
3. Herbs with glabrous stems; style hooked in fruit
....................... Laportea
3. Shrubs with pubescent stems; style none or not
hooked.
4. Cystoliths radiate on upper leaf surfaces; stinging
hairs none; flowers sessile and clustered along
branched spikes; pistillate calyx 0 (ours) but pistil
subtended by 2 tiny bracts ...... Gyrotaenia
4. Cystoliths scattered on upper leaf surface; stinging
hairs often present; flowers shortly stipitate and
clustered at apices of dichotomously branched
panicles; pistillate calyx equaling pistil, 4-lobed,
accrescent and fleshy in fruit ........ Urera
2. Inflorescence in axillary glomerules.
5. Shrubs; leaves markedly unequal in size at alternate
nodes ................... Boehmeria
5. Herbs; leaves k equal at alternate nodes.
6. Leaves entire, ovate to rotund ..... Rousselia
6. Leaves serrate, lanceolate. ........ Phenax
Boehmeria Jacquin
Boehmeria ramifora
Boehmerk romi~ora Jacquin, 1760:31.-Grisebach, 1860:160.
Dioecious or monoecious non-stinging shrub or tree to 6 m;
leaves alternate, serrate, acuminate-attenuate, markedly unequal
at alternate nodes, the smaller leaves shortly petioled;
flowers in compact axillary clusters.
Circumcaribbean; common in Dominica in moist, disturbed
areas 65-1000 m: Clarke Hall (Ernst 1004), Deux Branches
(Hodge 3113, Fon Pays (Hodge 2851), La Chaudieree (Hodge
3578), Laudat (Cillis 8194), Lisdara (Cooper 166, Hodge 645,
2408), Milton (Hodge 2883), Morne Aux Diables (Wilbur
8067), Morne Micotrin (Chambers 2686, Wilbur 8250), Mome
Plat Pays (Wilbur 7847), Pointe Guignard (Wilbur 7613), Pont
Casse (Lloyd 787, Webster 13457), Rosehill (Eggers 515),
South Chiltern (Hodge 1548, Nicolson 2174), Springfield
(Wilbur 7674), Sylvania (Hodge 644), Syndicate (Whitefoord
3498), Trafalgar road (Whitefoord 4641).
Gyrotaenia Grisebach
Gyro taenia crassifolia
Gyrotoenio crassifolia (Weddell) Urban, 1918a:159.-Kellogg in Howard,
1988, 4:74.
Urero crarsifolk Weddell. 185218; 1856:161.-Grisebach, 1860:155,-
Stehle et al., 1937, 1:185.
Large, dioecious, suffrutescent, and non-stinging herb to 6
m; stipules 2-3 cm long, united into a bicarinate ligule, soon
deciduous; leaves alternate, ovate, to 30 cm x 20 cm, serrate:
male plants with inflorescences near apex, female plants with
inflorescences remote from apex; male calyces with 4 broad,
imbricate, and ciliate sepals; female calyx 0 with 2 tiny
glandular-ciliate bracts clasping the edges of the flattened
pistil; stigma capitate-penicillate; achenes imbedded in swollen
fruiting rhachis.
Guadeloupe and Martinique; rare in ravines of interior
forests of Dominica: Boeri Lake (Whitefoord 4139 (8 and Q)),
upper Picard River north of Syndicate Estate buildings
(Nicolson 4169 (8), 4170 (Q)), Whitefoord 3968), sine loc.
(Zmay 206 at K, 271 at GOET).
This species is so rare and poorly known that it warrants
special comment. Female flowers of this species were unknown
to Urban (1918a:159). They are to be found on Stehle 1980
(US) from Guadeloupe and the above collections. These
confirm that this species belongs to West Indian Gyrotaenia,
not to mainland Myriocarpa. These genera are surely closely
related (both having 0 calyx but a pair of bracts subtending the
female flowers), the principal differences being that Myriocarpa
has shortly stipitate female flowers, with a distinctly
elongated style and an oblique, rather elongated stigma (often
slightly 2-forked), while Gyrotaenia has sessile female flowers
and a subsessile stigma that is capitate.
Leaves of Gyrotaenia crassifolia have striking 1 sq cm
areoles with radiately oriented cystoliths around each (aborted)
hair on the upper leaf-surface. It shares this character with
Myriocarpa cordifolia and M. longipes. Leaves of G. crassifolia
look very much like Urera caracasana but the latter has
scattered or, rarely, weakly radiately oriented cystoliths. The
inflorescences of Urera (dichotomously many-branched and
with terminal, solitary female flowers or clusters of male
flowers) are very different in G. crassifolia (few-branching
spikes with lateral clusters of flowers).
Duss 2861 from Guadeloupe was cited by Urban
(1918a:159) as Gyrotaenia crassifolia but was mixed with