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PACIFIC SCIENCE, Vol. XV, April 1961 
pubescent but not densely silvery; with stiff 
hairs; compact shrubs usually 10 ft. tall or 
less. 
1. Petioles and nodes set with sparse 
long stiff hairs up to 5 mm. long; 
calyces rather sparsely scaly; ribs be- 
low sparsely scaly; lateral veins more 
or less glabrous 
Melastoma decemfdum (2) 
2. Petioles and stems set with numerous 
short spinules to 1 mm. long; nodes 
with a few long scales; calyces silky 
with numerous scales; ribs and small 
veinlets rather densely scaly-spiny be- 
low Melastoma malabathricum ( 3 ) 
1 .Tibouchina semidecandra (Schrank and Mart.) 
' Cogniaux 
distribution: Kauai: Kokee, open grass area 
by museum, on ditch bank by roadside, Dec. 23, 
1959, D. L. Plucknett 81-85. 
Hawaii: N.W. Kilauea Crater, wet fern for- 
est around houses, 1150 m., Aug. 30, 1933, Fos- 
berg 10121. Volcano Road, near volcano, forest 
reserve along road, in mixed fern forest, tall 
shrub 5 m. high, Nov. 10, 1926, L. H. Mac 
Daniels 223. Volcano House, July 24, 1926, 
Aug. 24, 1926, C. S. Judd. 29 miles, Glenwood, 
Hawaii, July 23, 1926, Degener 8188; June 22, 
1929, persistent in forested region, Degener 
9641. Glenwood, el. 1000 m., in forest, Dec. 
25, 1930, E, H. Bryan, Jr., 714. Kalanilehua, 
Aug., 1917, J. F. Rock 13029, 13030. Kurtis- 
town, Jan. 20, I960, along roadside, D. L. Pluck- 
nett 95- Hilo, May, 1932, A. Meebold. 
Oahu: Nuuanu Valley, upper part near Up- 
side Down Falls, well established in underbrush 
in thick woods, shrub 2 m. tall, flowers deep 
purple, Fosberg 27067, Sept. 15, 1946. Tantalus, 
grounds of E. F. Bishop, Oct. 3, 1930, H. E. 
Gregory. Observed, Manoa Valley, by Manoa 
stream, B. C. Stone, Feb. I960. 
Altitude range 1,500-4,500 ft.; requires moist 
relatively cool habitat. At lower elevations it is 
usually under shade, but at Kilauea Crater it may 
be found in the open (elev. 3,400 ft.). This 
species is a spectacular shrub and in cultivation 
is very attractive. It does not appear to be as 
aggressive as the two Melastoma spp. and tends 
to spread only in disturbed areas. It has not been 
found deeply penetrating the native forest, but 
is often very common along roadcuts, houselots, 
trails, and near buildings. 
2. Melastoma malabathricum L. 
distribution : Kauai: Kilohana Crater, dom- 
inant shrub, 320 m., 7 Aug. 1928, E. H. Bryan 
626. Reservoir near Hanahanapuni Crater, Mar. 
24, I960, Plucknett 1 16, 117. Wailua bauxite 
project area, Mar. 24, I960, Plucknett 118-123. 
Hatvaii: Anauulu Rd. above Hilo, side of 
gully in canefield, flowers pink, Dec. 7, 1933, 
alt. 400 m., Fosberg 10490. Kaumana, alt. 200 
ft., flowers pink, Sept. 1953, Amy Suehiro. Ke- 
aau Orchard- Volcano Highway Intersection, by 
roadside, Dec. 4, 1959, Plucknett 78. Hilo-Vol- 
cano Road, 4 miles mauka, Jan. 20, I960, road- 
side, Plucknett 93, 94. Hilo radio tower, Jan. 
20, I960, Plucknett 89, 90, 92. 
Altitude range 0-1,000 ft. In contrast to Tib- 
ouchina, Melastoma malabathricum is tolerant 
of drier and warmer habitats and tends to spread 
in lowland areas rather than in disturbed areas 
of native forest. Usually found in open habitats 
such as pastures, waste areas, and fields with 
weedy vegetation. On Kilohana Crater on Kauai 
and the adjoining areas where it once was dom- 
inant, Rhodomyrtus tomentosa (Ait.) Hassk. 
appears now to be replacing it, but it still re- 
mains an important weedy species in this area. 
Pope’s reference (1929: 147) to Melastoma 
decemfidum on Kauai is probably in error since 
only M. malabathricum has been found on that 
island. The plant is known on Kauai as "Isen- 
berg bush” probably because of its association 
with Kilohana Crater and the Isenberg home 
there. Rhodomyrtus tomentosa has also been 
called "Isenberg bush” on Kauai but it more 
commonly is known as "Indian gooseberry.” 
On Hawaii Melastoma malabathricum may be 
found in great abundance in the Keaukaha area 
near the Hilo Airport and along the Volcano 
Road. 
M. malabathricum is vigorous in growth and 
spreads rapidly from numerous seeds, usually 
spread by birds. 
3. Melastoma decemfidum Roxb. 
DISTRIBUTION : Hawaii: Hilo, sent to J. Kim, 
Honolulu, B. Ag. Forestry, 10 Dec. 1957. Hilo- 
